I picked up a hot circuit off one of the ceiling lights, put a illuminated rocker switch on the wall near the bathroom door (rear wall) so I can energize the camera by reaching in. I didn't want the cam energized through a clearance light because my cam is an observation / backup cam. My plan is to use it (and I do) while driving. Really eliminates any blind spots (and lets you see out the back) when going down the road.
Makes lane changes effortless, lets you see tailgaters and 'observe' your trailer on the back (if you pull a trailer). I have a Furrion wireless Cam.