Older homes are full of two-slot outlets, and the advice about them swings between "rip them all out tomorrow" and "they've been fine for 60 years." Both takes skip the actual question. A two-prong outlet is an ungrounded outlet: it delivers power fine, but it has no third wire to carry fault current safely away. What that means for risk — and what your real options are — depends on what you plug into it.
In a grounded outlet, the round third hole connects to a wire that runs back to the panel and into the earth. Its job shows up only when something goes wrong. If a hot wire inside a metal-cased appliance comes loose and touches the case, the ground wire gives that current a low-resistance path home, which trips the breaker fast instead of leaving the case energized and waiting for a hand to complete the circuit.
Without a ground, that fault sits there silently. The appliance works normally — which is why ungrounded outlets feel fine day to day. The risk is real but specific: it's about faults in equipment with metal cases and three-prong plugs, and about anything used near water. It's also why the honest first step is testing rather than assuming — plenty of three-slot outlets in old houses have no ground behind them, and our guide to telling whether an outlet is actually grounded shows the three checks that separate the two.
| Load | On an ungrounded outlet | Why |
|---|---|---|
| Lamps, phone chargers, radios | Generally fine | Most are double-insulated with two-prong plugs by design — there's no ground to miss |
| TVs, game consoles, small electronics | Low shock risk, but no surge path | Surge protectors need a ground to divert spikes; without one they're power strips |
| Computers and office gear | Ground recommended | Three-prong supplies expect a ground for fault protection and surge shunting |
| Metal-cased appliances (toaster oven, power tools, washers) | Highest concern | A case fault with no ground path is the classic shock scenario the ground wire exists for |
| Anything near water (bath, kitchen, laundry, garage) | Wants GFCI protection regardless | Water drops body resistance and raises fault stakes — protection matters more than grounding here |
Option 1: Leave low-risk outlets alone. For a bedroom lamp circuit that will never run anything bigger, this is a legitimate answer, not neglect. What doesn't belong in this category is the cheater adapter — the little two-to-three-prong plug with a metal tab. The tab only grounds the adapter if the box behind the outlet is itself grounded, which is the very thing that's missing. It fixes the shape of the plug and nothing else.
Option 2: GFCI protection — the code-legal fix. The National Electrical Code expressly allows an ungrounded outlet to be replaced with a GFCI outlet. A GFCI watches for current leaking out of the circuit — as little as 5 milliamps — and cuts power in a fraction of a second, which protects people from shock without needing a ground wire at all. Two conditions come with it. The outlet (and any standard outlets it protects downstream) must carry the "No Equipment Ground" label from the box, because protected is not the same as grounded. And it still gives surge protectors nowhere to send a spike, so computers still belong on a true ground. If a protected outlet starts nuisance-tripping afterward, our guide to a GFCI that keeps tripping separates a real ground fault from a dying device. An electrician typically charges $100–$250 per outlet for the swap, parts and labor; the device itself runs $15–$30.
Option 3: A GFCI breaker for the whole circuit. Protecting the circuit at the panel covers every outlet on it with the same shock protection, labeled the same way. The breaker itself costs more ($40–$80 versus $15–$30 for an outlet), and panel work is electrician territory, full stop — but on a circuit with six ungrounded outlets, one breaker can undercut six outlet swaps.
Option 4: Run a real ground — the complete answer. An electrician pulls a ground wire to the outlets that need one, or rewires the circuit. It's the only option that makes surge protectors work properly and satisfies three-prong equipment fully. Pricing runs roughly $150–$300 per outlet when basement or attic access is open, and it climbs fast when walls are closed. Whole rooms or whole houses roll into rewiring territory — the warning signs in our rewiring checklist help you judge whether your house is headed there anyway, in which case grounding rides along with that bigger job instead of being paid for twice.
Test before you spend. Some two-prong-era homes have grounded boxes or partial upgrades. Map which outlets are actually ungrounded first.
Protect the wet and heavy locations. Bathrooms, kitchen counters, laundry, garage, and the outlets running metal-cased appliances get GFCI protection first — that's where the fault risk concentrates.
Ground the electronics location properly. The desk or media corner gets a real ground run if access allows, so surge protection actually functions.
Fold the rest into future work. Remaining low-risk outlets can wait for a panel upgrade or rewire, when opening walls and running wire is already on the bill.
Two-prong outlets are a limitation, not an emergency. Leave the lamp circuits alone, put labeled GFCI protection where water and metal-cased appliances are, and pay for real grounds at the few outlets that feed your electronics. The two answers to refuse are the cheater adapter presented as a ground, and the bootleg jumper presented as a fix — both trade a small, understood risk for a hidden, bigger one.
They're generally legal to keep. Existing installations are typically grandfathered — the code governs new work, not retroactive upgrades. Landlords and sellers face disclosure and local-rule variations, but a homeowner isn't usually required to replace working two-prong outlets.
You can physically, but it doesn't add a ground. The adapter's tab only works when the outlet box behind it is grounded metal — which ungrounded two-prong installations usually aren't. Treat an adapter as a shape converter for low-risk loads, never as protection for a computer or a metal-cased appliance.
Yes — shock protection is exactly what it provides without one. A GFCI compares current going out to current coming back and trips on an imbalance of about 5 milliamps, which doesn't depend on a ground path. It must be labeled "No Equipment Ground," and it doesn't give surge protectors a path, so it isn't a substitute for grounding electronics.
Not properly. A surge protector diverts voltage spikes down the ground wire; with no ground, the spike has nowhere to go and the unit behaves like a plain power strip. Computers and TVs you care about belong on genuinely grounded outlets.
GFCI protection runs about $100–$250 per outlet installed by an electrician, or $40–$80 for a GFCI breaker plus labor to cover a whole circuit. Running a true ground costs roughly $150–$300 per outlet with open access from a basement or attic, and more where walls must be opened — which is why most homeowners ground a few key locations instead of the whole house.