My son's 98 Grand Cherokee has me stumped. Recently the battery was dead and I assumed he had left a light on inside. Sure enough when I charged the battery and re-installed it, all the interior dome lights immediately went on. I tried turning them off (they are pushbutton style), but they won't go off. After some investigation I replaced both door jamb switches but that didn't help. I've pulled the fuse to save the battery, but I can't figure out where else these things could be turned on! Any suggestions appreciated.
P.S. I made sure the slider switch beside the headlight switch was off too.
I had the same thing happen with my ZJ and never did figure it out, either. Luckily, that fuse doesn't serve anything else, so I just left it out and stuck one of those Harbor Freight LED puck lights in the center console for the few times I needed light. Sorry I can't offer more help.
The slider all the way up turns all the interior lights on as would the rear hatch being open / bad liftgate sensor. Try lower the slider a hair. Also the rear interior light just inside the hatch can be pushed in a click to also turn them off provided the slider isn't all the way up.