Interior lights stuck on

[87Skier]

My 89 Suburban's interior lights won't shut off. I tried slamming all the doors, messing with the door switches on every door but nothing seems to work except removing the wire from the fuse block. Also the rear passenger doors have never operated the interior lights.

Not sure where the issue is, but hitting a really rough road usually shuts them off temporarily before some more bumps makes them come back on.

I'm thinking there is an intermittent short somewhere, but don't know where to look. Any suggestions?