JC - that little red light in my coach turns on the outside smartbed switches, so the outside wall mounted switches operate those same smartbeds. Additionally, it also provides power to the lights in each smartbed so when it opens the light is on. Leave it off unless you are going to operate the smartbed using those switches, as I believe the lights stay one all the time. If that is the case, they get hot, the light fixture housings will melt and a fire could start. If you need access then turn them one with that switch, and once finished then turn it off. Hope this helps.
All this assums that you have smartbeds, which is outlined in the manual (assumed you have one) of the coach. If you don't I could take my SE manual up and have it copied and send it to you, if you would pay for that and the postage.
Monty & Janet - 2007 Alpine APEX 40 MDTS
S/N - 75715 - Retired - Master Certified RV Tech