Hey this weekend was sitting in driveway waiting for a friend and I noticed the security light came on any ideas. Doesn't affect anything just one of those PITA things. Anyway shut off truck a little while later and light went off. The only wierd thing I did is as I was waiting I threw in some PS anti gel as weather was supposed to drop last night. I don't know if that would have anything to do with it.

The door sensor tends to wear the pad that it push against out. Leaves a little mark. It's enough that when your leg or arm pushes a little on the door it turns the light on. If it gets bad enough even some good bumps will do it.