2002 Ford F150, Mileage 78000, 5.4 engine. We have been having light problems. It started with the tail lights not coming on, then no lights would turn on. We got a few suggestions, and changed the fuses, now the lights will turn on, but will not turn off. We have to remove the fuse and put it back to get the lights off. We have tried changing the switch, fuses, relays, and even got a new GEM module. The problem is still not fixed. What else could it possibly be?