Some of the stories about lights going on and off reminded me of something. When lights go on and off without reason most people calmly explain that it's an electrical problem, but when electricians start talking about lights going on and off for no reason...
My ex is an electrician, and years ago he was working temporarily for a contractor based several hundred miles away - leaving Sunday night and coming home Friday afternoon - so far not unusual. One Friday he casually mentioned that this contractor had offered him a permanent job, complete with a place to live. Maybe I heard something in his voice, or maybe it was one of those unsettling moments of mind-reading we'd do sometimes, but without even thinking about it, I responded "I'm not living in a haunted house."
Well he looked thoroughly
and said he hadn't even believed this guy's story.
When the electrical contractor had bought the house he had started the furnace and then left it for a few days to give it time to warm up (they're snuggled right up against the Canadian border, so an area that gets quite cold in the winter). He went back accompanied by one of his employees, who had offered to help him out, and the furnace was off.
So, of course, the first thing they did was go down to the basement assuming incorrectly that a breaker had been tripped, and to see if the problem was the furnace or the wiring in the house. Well, while they were down there the lights upstairs went off. When they were upstairs trying to figure out what was wrong with those lights, the lights in the basement went off. When they went back down to the basement, the lights upstairs came back on.
Which is apparently when they left for the day, in a little bit of a hurry.
Of course, being a skeptical sensible sort, and understanding what causes these things, he went back in later with a flock of electricians and had them test all the wiring in the house. They didn't find anything wrong, but most of the wiring in the house was replaced anyway - it was older, and not altogether up to code - and the furnace as well for good measure.
Which didn't fix the problem, and the lights would still sometimes go off and on by themselves. Although not with such alarming regularity.
We didn't move in the end, ex didn't take the job, the house was a factor in the decision but not the main one.