'99 CV interior lighting issue

My dad has a '99 CV that just developed a lighting problem.
The interior lights (one on the ceiling and one under the dash on the driver's side) are supposed to dim and then go out shortly after closing the door. They are now staying on for about 10 minutes or so before going out. I'm afraid that whatever is going wrong will only get worse and then they'll be stranded somewhere with a dead battery. If I had to make an uneducated guess, I would think that there must be some sort of a timing circuit involved in this lighting control and that it is beginning to fail. Your input, as always, regarding this matter is greatly appreciated. Thank you.

Sorry so late to respond. First thing to do is spray each door latch real good with penetrrating oil to be sure the switches are not hanging. If this does not help any, you probably are looking at the lighting control module. This controls all the interior and some exterior lighting.