Farmer Jim, I have similar switches. The one in the entrance next to the main cabin switch turns on the lights in the entertainment cabinet (if the switch on the fixture in the cabinet is also on). The two going into the front bedroom area turn on the vanity lights and the overhead light (again assuming the fixture switch is also on). It may be matter of trial and error turning on the fixture switches and the one on the wall until you find the one that it controls, but I bet it controls one of them.
'01 Ford F250 CrewCab