Interior lights stay on - 2000 Jeep Cherokee

Either the lights are turned on manually from the headlight/interior light switch, or you have a defective door switch that is telling the module that a door is open, or you have a door that is open, or your module that controls the interior lights is defective. I would start with the simple things, I would make sure all doors are closed. If they are, then check the headlight/interior switch to make sure the interior lights are in the off position, then check all of the door switches. They are simple normally closed push button switches that should be mounted on the car frame near the door hinges.