My guess is that it is a battery on/off switch?
I had a 1988 Jamboree that had an on/off rocker switch tucked up inside the power cord storage area that turned on/off the outside light on the driver side near the hookups. I never knew how to turn that stupid little light on for about 5 years till my dad mentioned it (he had owned the same model years earlier).
You don't stop playing because you grow old...You grow old because you stop playing!
2004 Itasca M30W