I have a tv hookup in BR. If I connect a cable to it and put up antenna, I get "over the air" reception. If the campground has cable at the post with water/electric and I connect a cable from my fiver...
This button on your TV ANTENNA WALL COVER PANEL is the override. When the light is 'ON' it uses the OTA ROOF MOUNT antenna. When 'OFF' it uses the CABLE TV INPUT signal from the camp ground.
That is the way it works in my two trailers at any rate...
Of course after I have selected which ANTENNA INPUT to use I have to go to the TV MENU and select the proper input ANTENNA or CABLE and scan in the channels before I can view them...