To whom it may concern, I just bought a house that was built in 1958. When the house inspector went through the house, he noted that our main fuse box was grounded at the breaker, and then randomly tested various plugs throughout the house and they were grounded. GCFI plugs were installed in the bathroom, kitchen and garage areas respectively. Unfortunately renters were in the process of moving out and furniture was blocking maybe five or six outlets. When the furniture was moved and we finally took possession, we noted around 5 outlets were two pronged. I was planning to test for ground using a voltage tester, by plugging the leads into the polarized plugs (following directions for which color goes where) and then move the lead from the small plug to the screw on the outlet and if the voltage doesn't change then it's grounded. I don't have much money and can't afford to rewire the house. Regardless of how the plugs come back, I'm planning on replacing the receptacles with GCFI outlets. Is there anything else I should do, that won't cost me too much? I don't plan on plugging a TV or computer into the GCFI receptacles, just fans, a phone charger and clock radio because it's in the bedroom.

Rantin' Robin

  • In many locales, GFCIs are only required/recommended in wet areas like the kitchen or bathroom. You likely wouldn't be required to replace all your receptacles with GFCIs, and it'll save you money to just install regular 3-prong outlets. Multiple GFCIs on the same circuit are redundant anyhow, you can just have one on the first receptacle on the circuit and have the same protection. Oct 27, 2020 at 19:52
  • Can you post photos of the insides of the boxes for said two-prong outlets? Oct 28, 2020 at 0:18
  • Your test won’t tell you much of anything useful - remember ground and neutral are ultimately bonded. Your test can’t tell the difference between a properly grounded receptacle and one whose frame is connected to neutral. You need to at least open up the boxes and look at the wires.
    – nobody
    Oct 28, 2020 at 3:45

1 Answer 1


It may already be grounded. Back in the day, it was common to use either metal conduit or metal-armored cable, which provides a ground path.

If you only need human-safety protection and not equipment protection (e.g. from ESD), then you can convert 2-prong receptacles to 3-prong by providing GFCI protection. You must add a sticker "No Equipment Ground", and if the GFCI device is somewhere else, also "GFCI Protected".

If one is clever, and if one is poor it pays to be clever, then one can get by with a single GFCI device per circuit. The labeling is still required.

Lastly, it is legal to retrofit just a ground wire to a box that has no ground. The ground wire must be the proper size for the circuit, and must go back to either a) the panel, b) a junction box with metal conduit going back to the panel, c) a junction box with a big enough ground wire going back to the panel, or d) the bare copper Grounding Electrode System wires.

  • How would I know where a circuit is in my house, so that I can use only one or two GCFI plugs? Oct 27, 2020 at 17:28
  • 1
    Map your breakers. Plug something into every outlet, turn off all your breakers, then turn on one at a time and figure out what it powers. Oct 27, 2020 at 17:36

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