What is this switch for?

ddschuman wrote:
My mom & step dad purchased a 2017 Salem 27RKSS a couple of weeks ago. Today, she noticed a switch that she had not noticed during PDI and it was not explained. It is down low on the wall near the floor by the door adjacent to fire extinguisher. Please note, my mom is nearly 70 and has never owned a travel trailer before now. The travel trailer is sitting in her driveway at the moment and because they didn't disconnect the battery and it is not currently plugged in, the battery is dead so turning it on & searching to see what came on is not an option at the moment. She is blowing my phone up and driving me crazy trying to find out what that switch is for lol. Does ANYONE know??? She lives in another town from me but I may have to go see if ya'll have no suggestions. Thanks in advance!