Been trying to fix a circuit at my mother's house. Her place had some really old wiring along with newer. The circuit with the problem is the older wiring. She said she had electric heater plugged in and she saw a spark and the power went out like the breaker was tripped but at the breaker box all was good. I checked each breaker for 120 and they all were good.

Spent a day and could not get power to come back to that circuit. Later that night we were relaxing and the power decided to come back on. I have moved wiring and all kinds of stuff to try to see if there was a short but so far I can't make it do that again. Last night I turned on light and it flashed and now is off again.

I changed the switch the first day so it's not that. But this is the old wiring with the metal around the wire. Would think I could make it do it again my moving wire if it was a short right? I'm going to go over the whole circuit very carefully today. My outlet tester said it has a open ground.

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    Just a quick note. This isn’t a “short”. A short circuit would trip the breaker (or if the breaker failed, possibly start a fire). You have an open connection.
    – DoxyLover
    Oct 5, 2020 at 12:44
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    "at my mother's house" indicates you don't live there. Technically, if you do the work, that's illegal. If you assist your mother in completing the work, I believe you're OK. While it's highly unlikely that anyone would ever know or even ask, should something go wrong, it could lead to issues, like with an insurance claim. Something to bear in mind.
    – FreeMan
    Oct 5, 2020 at 13:12
  • @FreeMan in my jurisdiction there's one more condition: for hire. Here an unlicensed individual may work on their own primary residence, and they may have the help of other unlicensed individuals so long as there's no more than "nominal" compensation -- think pizza, drinks, etc -- so that it's clear the unlicensed assistant isn't contracting, ie doing the work for hire.
    – Greg Hill
    Oct 5, 2020 at 16:26
  • Just issuing a general caution, @GregHill, based on some of my reading here. I'd hate for someone's house to burn down then have the insurance co rub salt in the wound by refusing the claim...
    – FreeMan
    Oct 5, 2020 at 16:28

1 Answer 1


There's only one solution, and that's to trace the circuit and examine every connection. You have a loose screw or a broken wire somewhere that's arcing and losing contact. That's where fires start.

I would take the opportunity to replace the devices where they're more than a few years old (both switches and outlets wear out), and make sure you have a good understanding of how to make connections safe. Don't use the stab-type connectors that some devices offer. Use the screws with good loops and use pigtails where necessary.

If you do that and the problem doesn't resolve you'll have to assume a broken or damaged wire in some concealed location.

Be sure to do some reading on house wiring first. Your confusion over the definition of a short demonstrates a lack of basic knowledge. You don't want to make the problem worse with incorrect technique. Or get professional help.

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