How would I test for a good or bad switch, receptacle, GFCI, breaker, or fuse?
(Also see Testing). If a hooked up non-dimmer non-3way switch shows hot at one terminal (neon tester in hand) but not at the other when the switch is turned to ON, the switch is bad. Or just join the switch’s two wires; if the light works but didn’t for the switch, the switch is bad. A receptacle may need replacing but that will be from not holding plugs well, or from it having overheated from a poor wire connection, or from being simply broken. These things need looking for; there is no other way of testing for “badness”. If a GFI that can run things won’t trip off for the test button, replace it. And if a GFI with good hot and neutral at its line terminals won’t reset and run things when no load wires are connected, replace it (I have seen this only once or twice). Other than these, the GFI itself is good. A breaker’s screw showing hot for your neon tester is good 95% of the time. If moving a breaker’s wire to another breaker changes nothing in the circuit’s behavior, the breaker was
