I don't really believe my house is possessed, but I've got an electrical problem that has me totally stumped. Been living in this 1979 house for two years. Out of the blue, at about 12:30am a couple of weeks ago, the courtyard lights go on by themselves. (It wakes me up and I'm a little wigged when it happened thinking, "intruder?"). Nope; they just turned themselves on. It's happened almost daily since. Most of the time (maybe a little more than half the time) it happens around (but not exactly) the same time of night. Not always, sometimes its other times of the day. All I can think is maybe one of the switches is failing.
There are two 20A 3-way switches controlling these lights; one inside and one outside in the courtyard. I'm thinking after the 30 years, the exterior switch is the likely culprit. I replace it. An hour later, the lights turn themselves on. Next day, I replaced the interior switch. Same result.
I'm stumped. When the lights turn themselves on, the switches exhibit an odd behavior:
After they turn themselves on, toggling either switch on its own will not turn them off. For example, if I go the interior switch and it's in position A switching from A to B won't turn them off. A-B-A-B-A-B... they stay on. Same on the outside switch. However if I toggle a switch by one position, for example, I turn the interior switch from A to B; then go outside and do the same thing, the lights will turn off. AND, not only have I turned them off, but now both switches operate exactly as expected: either switch will turn the lights on and off.
There's no third switch that I'm aware of. No light switches in the house that I don't know what they do. I've got the original architect's electrical plan: only two switches on those lights.
Any ideas? (Other than the exorcism!)