There should be a integrated switch that turns on the backup lights when the transmission lever is moved to the reverse position. Not too unusual for this switch to stick in the on position after the transmission is shifted out of reverse. Not sure where to find the switch on your unit, most likely under the coach or under the dash would be my guess.
Days camping (2016)----181 days
Days camping (2017) --- 21 days
2016 Wildcat MAXX 28RKX (33' TT), 2007 13' Scamp
2015 Ram Laramie Hemi, w/air suspension
30 years RV'ing
12 different RV's