Movement while driving
Hit a pot hole or railroad tracks or heck
even bumping the steering wheel the
interior lights come on and the seat
Weird, it sounds like the door ajar switch is activating and the power seat. Check the connection of the battery cables on the battery. They might be loose or corroded. Remove and clean the real good. If they are OK, maybe one of your ground wires has the same issue.
I agree with a door switch, possibly worn door hinges, weatherstrip, even the latch itself, start with the drivers door first.