Fuse problem in my 2002 Jeep Liberty

The fuse that controls my radio, the rear door, interior lights and locks keeps blowing. I’ve had it into the dealership 3 times and they can’t figure it out - no loose wires, they say. It’s not the radio (by process of elimination). It has 104,000 miles on it and has been virtually free of problems until now. Any ideas??? Thanks!