By Alexandr Godonoaga, Owner and Lead Electrician, Cob Services LLC. Illinois Electrical Contractor License #26-00032356. Published March 2026. Rewritten and technically reviewed September 5, 2026.
Grounding usually comes up in one of two ways. A home inspector points at a two-prong outlet during a sale, or somebody feels a tingle off the toaster and starts searching.
Both are worth taking seriously. But most of what gets written about grounding is built on an analogy that is wrong, and the wrong analogy leads homeowners toward the wrong repair. So let me start by taking apart the one you have probably read.
The drainpipe analogy is backwards
You have seen this: electricity is like water in a pipe, and the ground wire is the drain that carries stray current safely into the earth.
It is a nice image and it is not how any of this works. The earth is a poor conductor. Dirt cannot carry enough current to trip a breaker. The NEC says so directly in 250.4(A)(5): the earth shall not be considered an effective ground-fault current path.
Here is what actually happens. When a hot wire touches the metal case of your dryer, the equipment grounding conductor gives that current a low-resistance path back to the source, through the panel and the main bonding jumper to the utility neutral. That path lets a very large current flow for a fraction of a second, which is exactly what a breaker needs in order to trip. The ground wire’s job is not to drain electricity away. Its job is to cause a fault big enough and fast enough to shut the circuit off before the metal case can hurt you.
The ground rod outside your house does something different. It stabilizes voltage relative to earth and gives lightning and induced surges somewhere to go. It does not clear faults.
Why this matters practically: because the fault-clearing function depends on a continuous metal path back to the panel, the questions that matter are about continuity and bonding, not about how deep your ground rod is. Everything below follows from that.
In this area, a two-prong outlet does not mean you have no ground
This is the point I most want older-home owners around here to take away, because it changes the cost of the fix by thousands of dollars.
The NEC recognizes several things as equipment grounding conductors besides a green or bare wire. Metal conduit and the armor on BX cable both count, under the conditions listed in 250.118. And a great many homes in Naperville, Downers Grove, Hinsdale, and the older parts of Aurora were wired in metal conduit or armored cable, because that was the standard practice in the Chicago area for decades in a way it was not in much of the country.
What that means: your house may have two-prong outlets and a perfectly usable equipment grounding path sitting in the metal box behind them. In that case, replacing them with proper three-prong grounding receptacles bonded to the box is straightforward and legal. No rewiring, no fishing walls.
It is not a guarantee. Conduit systems develop breaks at couplings, someone spliced in NM cable during a 1970s remodel, a run got extended into a plastic box. But it is common enough that anyone telling you a two-prong outlet automatically means a whole-house rewire has not tested your boxes.
Testing takes minutes per outlet with the right meter. It is the first thing we do, and it is the difference between a receptacle replacement and a rewire.
Why the $10 plug tester on your counter cannot be trusted
Those three-light outlet testers are useful for what they do, and homeowners over-rely on them for what they cannot do.
A plug tester checks whether the ground pin has continuity to something at neutral potential. It cannot tell you whether that something is a real equipment grounding path or a piece of wire somebody jumpered from the neutral screw to the ground screw inside the box.
That second thing has a name. It is called a bootleg ground, and it is more dangerous than having no ground at all.
Here is why. An outlet with a bootleg ground reads “correct” on every homeowner tester. But the ground pin is now tied to the neutral. If that neutral ever opens upstream, which happens with loose backstab connections and corroded splices, the metal case of everything plugged into that circuit becomes energized at line voltage. An ungrounded outlet is a known risk you can plan around. A bootleg ground is a hidden one that reads green on a tester.
We find these regularly in houses where someone swapped two-prong outlets for three-prong ones before a sale. That is the actual version of the “Ferrari body on a golf cart” problem, and it is worth checking for specifically if your home changed hands in the last twenty years.
Testing for it requires a meter and knowing what to measure. It is not something a plug-in tester will surface.
Your options if an outlet genuinely has no ground
The code does not force you to rewire. NEC 406.4(D)(2) gives three ways to replace a receptacle where no equipment grounding conductor exists in the box, and there is a fourth path worth knowing:
Option one: replace it with another two-prong receptacle. Legal, cheapest, and it keeps the situation honest. It also keeps you reaching for cheater adapters, which is how people end up with bootleg grounds.
Option two: install a GFCI receptacle, marked “No Equipment Ground.” This is the option most homeowners have never heard of and it is often the right one. A GFCI does not need an equipment grounding conductor to function. It compares current out against current back, and it trips on the difference, ground wire or not. You get real shock protection at one outlet’s cost.
Option three: install grounding-type receptacles fed through an upstream GFCI, marked “GFCI Protected” and “No Equipment Ground.” This is how you get three-prong outlets throughout a room without rewiring it, protected by a single GFCI at the head of the run.
Option four: run a separate equipment grounding conductor to that outlet, from one of the points permitted in 250.130(C). Not always practical, but on a single stubborn circuit it beats rewiring the house.
One limit worth knowing before you plan a remodel: these allowances apply to replacing an existing receptacle. If you extend the circuit and add a new outlet, the new one has to be a grounding type connected to a real equipment grounding conductor. So “I’ll just add two outlets off that old circuit” is usually not available to you.
What GFCI protection does and does not cover
The original version of this article called grounding plus GFCI the gold standard, which is right, but the reason matters and gets muddled constantly.
GFCI protects people. It watches for current leaking out of the intended path, including through a person, and cuts power in milliseconds. It works on an ungrounded circuit. It is the single best thing you can do for shock safety in an old house.
GFCI does not protect equipment. It will not stop a surge from killing a television, and it does not give a surge protector something to shunt into. Those are different problems with different devices.
AFCI is a third thing again. Arc-fault breakers detect the signature of arcing, which is a fire risk rather than a shock risk, and current code requires them across most living areas of a dwelling. If you are having circuits worked on in a house from the 1950s, this comes up.
The electronics question, answered properly
The claim that your expensive television “needs a place to send surges” is not quite right, and the correct version is more useful.
A plug-in surge strip works by shunting excess voltage into the equipment grounding conductor. On a circuit with no ground, the strip’s main protection mode has nowhere to go. So the $30 strip behind your TV is doing considerably less than the packaging implies in an ungrounded house.
The real answer is a whole-house surge protective device at the panel, and here is the part most homeowners do not know: it is now required. NEC 230.67, introduced in the 2020 code cycle, requires a Type 1 or Type 2 SPD on services supplying dwelling units, and it explicitly applies when service equipment is replaced, not just to new construction. The 2023 cycle expanded the occupancies covered and added a minimum discharge rating.
Practical consequence: if you are upgrading a panel in Naperville, which enforces the 2023 NEC, or in Downers Grove, which enforces the 2020 NEC with Village amendments, surge protection is part of the job. It is not an upsell. Any contractor quoting a panel replacement without it is quoting a job that should not pass inspection. Our electrical panel page covers what that work involves.
Bonding, which almost nobody writes about
Grounding gets the attention. Bonding is where we find more real problems.
Metal water piping. The code requires interior metal water piping to be bonded. In practice, the failure mode is a plumber replacing a section of galvanized or copper pipe with PEX and unknowingly breaking the bonding path across that gap. The plumbing works fine. The electrical bond does not, and nobody notices until an inspection or an incident. If you have had partial repiping done, this is worth checking.
Gas piping, especially CSST. Corrugated stainless steel tubing, the flexible yellow gas line used widely in homes built and remodeled since the 1990s, carries specific bonding requirements from its manufacturers because of documented damage from nearby lightning strikes. The bonding conductor is a defined size and lands at a defined point. We find it missing or undersized fairly often in homes where the gas work was done separately from the electrical.
Panel bonding. The main bonding jumper at the service, and correct separation of grounded and grounding conductors in subpanels, is the piece the entire fault-clearing path depends on. It is also one of the more common things done wrong in owner-installed subpanels.
None of this is visible to a homeowner. All of it is checkable in an hour.
Selling a house in the western suburbs
An ungrounded system is one of the first things an inspector flags, and the negotiation that follows is usually worse than the repair.
Two pieces of practical advice. First, get it tested before you list rather than after you are under contract, because the buyer’s inspector will describe the problem in the broadest possible terms and you will have no time to establish that half your boxes have a usable grounding path. Second, if you have three-prong outlets in a house old enough to have had two-prong ones, have them checked for bootleg grounds specifically before an inspector finds them for you.
Permits
In Naperville, an electrical permit is required before any electrical work begins, and the work must be performed by a state-licensed electrical contractor registered with the City. Downers Grove requires a permit through its online portal with a first review of roughly 10 business days. Receptacle replacement scope varies by municipality, so we confirm with the building department rather than assume.
Frequently asked questions
Does a two-prong outlet mean my house is not grounded? Not necessarily, and in this region often not. Metal conduit and armored cable are recognized equipment grounding conductors under NEC 250.118, and both were common in Chicago-area construction. Many older homes here have a usable grounding path in the metal box behind a two-prong receptacle. Testing determines it.
Can I just replace two-prong outlets with three-prong ones? Only if a grounding means actually exists in the box. Installing a three-prong receptacle with no ground behind it is a code violation and misleads everyone who uses it afterward. Where no ground exists, NEC 406.4(D)(2) permits a two-prong replacement, a GFCI marked “No Equipment Ground,” or grounding-type receptacles fed through a GFCI and marked accordingly.
Is a GFCI as good as a real ground? For shock protection, a GFCI is excellent and does not need a ground wire to work. It does not restore the equipment grounding path, so it does not help surge protectors or equipment that needs a ground reference. The two solve different problems.
What is a bootleg ground? A jumper installed inside the box between the neutral and ground terminals to make an ungrounded outlet read correct on a plug tester. It is a serious hazard, because if the neutral opens upstream, the ground pin and anything connected to it can become energized. Plug-in testers cannot detect it.
Do I need a whole-house surge protector? If you are replacing your service equipment, yes. NEC 230.67 has required a Type 1 or Type 2 surge protective device on dwelling unit services since the 2020 code cycle, and the requirement applies to service equipment replacement as well as new construction.
Does an ungrounded system have to be rewired? Usually not all at once. Between existing metal grounding paths, GFCI protection where no ground exists, and running an equipment grounding conductor to individual circuits, most houses can be brought to a safe and compliant condition without a whole-house rewire. A wiring update targeted at the circuits that need it is far more common than a full rewire.
Get it tested before you decide anything
The whole point of this article is that the right repair depends on what is actually in your walls, and that is a measurement rather than a guess. We test outlets and boxes for a real grounding path, check for bootleg grounds, verify bonding at the water and gas piping and at the panel, and then tell you which of the options above applies to your house.
We work throughout Naperville, Downers Grove, Lisle, Aurora, Plainfield, Bolingbrook, Hinsdale, Burr Ridge, La Grange, and the rest of DuPage and Will County. Call (630) 427-5923 or request a service visit.
Related: outlet grounding, outlet replacement, electrical panels, dedicated circuits, and residential electricians in Naperville.
About the author. Alexandr Godonoaga is the owner and lead electrician at Cob Services LLC, an Illinois-licensed electrical contractor (#26-00032356) working across DuPage and Will County for over a decade. Licensed, bonded, and insured.
Cob Services LLC 2020 Calamos Ct Suite 200, Naperville, IL 60563 (630) 427-5923 Monday through Friday, 9:00 AM to 5:00 PM
Code editions and local amendments vary by municipality. Requirements described here were verified on September 5, 2026 against the published code adoptions of the City of Naperville (2023 NEC) and the Village of Downers Grove (2020 NEC with amendments). Confirm with your building department before relying on any of it.