Sometimes a trailer is prepped for a backup camera with a separate power switch. Also, I have a switch that I didn't know what it did, but determined it was for an exterior light on the opposite side of the trailer from where the switch was located.
John & Jennifer and family
2018 Jayco White Hawk 31BH 34'
2004 Surveyor by Forest River 29'
1996 Coachman Catalina 25'
2002 Jayco 12UTD PopUp