mystery switch

I have a 2005 Winnebago sightseer 29r. In the cabinet on the right of the tv in the cab area is a button that when you push down a green light comes on and when you push it again the light goes off? Also the outlet plates in the cabinets next to the tv and also in the cabinet in the bedroom where that tv would be are black? There's one across from the refrigerator also? All the rest of the outlet covers are white and are in everyday use areas? An inverter was an option that the previous owner did not get. are these outlets pre-wired for a inverter?
Thanks