I drive a 98 S70 Base..The lights in the back seat don't work, both left and right, the ones with the hanger hook, not the door. Should the switch lock when you click it to one side? Both of mine are completely loose and I'm sure both bulbs aren't dead.

 

I haven't used mine yet, but they probably should. I would suggest either tightening every screw you can find or go to a junkyard.