I just bought a new-to-me 1999 class a winnebago. It has a switch on the drivers dash labeled "Remco". I think it has something to do with flat towing a car behind the motorhome. He was flat towing ...
My used towed had a speedo disconnect(illegal now) but the switch was in the towed. I would for no other reason than I was curious follow the load side wire and see where it went. You might find it by looking at the wires on the switch and then the towed connecter on the receiver hitch.
If it doesn't effect when turned on, you can probably just ignore it, me I'm curious and it would drive me nuts.