Question about a weird voltage reading in a 1920s house basement

I was troubleshooting a flickering light in an old Seattle basement and my meter showed 87 volts on a circuit that should have been dead, which made me double-check everything with a non-contact tester first from then on.

5 comments

5 Comments

skyler_jackson273mo ago

What was the non-contact tester reading?

morgan.rose3mo ago

You asked about the non-contact tester reading. Mine kept going off near an outlet but showed nothing on the wires themselves. Turns out it was picking up the low voltage from an old phone line buried in the wall right behind it. Those testers are so sensitive sometimes, you know? I had to trace the whole circuit to figure that one out.

violar353mo ago

Oh man, that makes total sense. I read a forum post once where someone's tester was going crazy because of an old doorbell transformer hiding in the attic. Those things can pick up the weirdest stray voltage, like from cables that aren't even live anymore. It's kinda spooky how they react to stuff you'd never think about. Makes you double-check everything before you trust a simple beep.

phoenix2461mo ago

Ha! Man, that takes me back. I was helping my buddy rewire his basement and his non-contact tester kept chirping like a cricket near a random spot in the ceiling. We tore out half the drywall looking for a hot wire, found nothing. Turns out it was picking up the signal from his neighbor's garage door opener that was on the other side of the wall. The thing was just sitting there in idle mode and the tester was going nuts. I felt so dumb after we figured it out, we must have spent two hours chasing that ghost signal.

jana_jones1mo ago

That's exactly the problem with those non-contact testers, skyler_jackson27. They're so sensitive they pick up any stray voltage, not just live wires. I had a similar issue where my tester kept buzzing near a baseboard heater, but it turned out to be the static electricity from the heating element, not a hot wire. It's a real pain when you're trying to troubleshoot a simple outlet and the tester throws you off. I learned the hard way to always double-check with a multimeter before drilling into anything. Those testers are useful for a quick check, but they can trick you if you're not careful.