Interior Lights are Haunted

Hi everyone. I have a '93 Eighty-Eight and the interior lights appear to have a mind of their own. When the engine is off and the key is in the accessory position, the interior lights will come on at random, stay on for about fifteen or twenty seconds, then shut off. Sometimes this will happen up to four or five times in a row.

At first I thought it might be caused by my moving around or accidentally pushing on the door or something, but they still come on even when I am perfectly still. I don't believe the lights come on when the car is off and the keys are out, but I haven't taken the time to study it so I can't say for sure.

Any ideas what cause this? Is this some sort of undocumented feature, and if it is, any ideas how I can stop it? It can be very irritating. Thanks for any ideas.