Our cars interior lights go on by themselves and go off. This is a problem as it has drained the battery. It seems to be vibation like motorcycles loud cars(muffler) etc. Have you clues? There is a security system but the alarm does not go off but the same lights go on/
The Grand Marquis has changed a lot through the years. What year is yours?
It is a 2000.
It’s probably the LCM (Lighting Control Module). It could be one of the door latch switches, but if that were the case you would probably be also complaining that you get a lot of door ajar indications while you are driving. Of course, it could also be a wiring problem, but the LCMs were known to have problems. I think that you could probably get better advice at: