TV Connection Plate

[winner]

This question for anyone having an Airstream 345 Motor Home

In the Salon area of my 1987 Motor Home, there is located in the TV Table on the wall, a plate where the Coax Connector is at the top of a wall plate, below it is a switch which lights a red light when it is push ON. Below that is a round "Port" similar to that found with a cigarette lighter. It is the same size as a cigarette light and has a raised rim.
There is nothing in the owner's manual explaining that wall plate or hooking up a TV, nor is there an explanation of the switch or the port below the switch which looks like where you would put a cigarette light.
If anyone call tell me what this wall plate is all about, it would be appreciated.