The Phantom Light

We have a spooky light problem in the den. I kind of noticed this a while ago, but put it down to not switching the lights on properly. Although really it's either on or it's off, no?
The track lighting is controlled by a three gang switch. One turns on the socket to the left of the den, the other two control the track lights; you can have them all on, just a spot that lights the picture on the east wall, there's one that lights all the spots on this wall and another that lights the south wall. And then there are the dimmer options. Oh yes we can micromanage the lighting in our den.
When we first moved in, we worked out which switches did what and then we only used the one that controlled the socket where we plugged a table lamp. Easy. Then one evening I wanted some extra light to illuminate the laptop and I turned on that spot. Nothing. So I turned the switch the other way.(They are rocker switches). Also nix. Then I went to the basement to check the fuse. It was on. I came back to the den and the spotlight was on. I decided I was crazy and forgot all about it.
Then on Monday we were putting up the last curtain pole at dusk, so Steve asked me to throw some lights on and nothing. I switched it one way, then the other. He was convinced that the fuse had gone so he sent me to check. When I got back having touched nothing in the fuse box the lights turned themselves on, then off, then on again. I guess that was the order I had fiddled with the switches but the expression on Steve's face was priceless.
Anyway I am not crazy, we have a forty-five second delay on the switch that wasn't there a year ago. So my question is: Is this dangerous? Or is it merely quirky and we should plan to put the lights on a while before it gets dark?