back up camera power supply

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.

IMO install a switch in the truck cab and run a wire with a weatherpack connector to the camper, it's nice to be able to turn it off and on from the cab. I used one of my upfitter switches for this purpose but that may be specific to Fords.

I also hooked it up to the Reverse wire in the 7 pin bundle so it automatically comes on when I switch to Reverse but can also be turned on via the upfitter switch. If you go this route put a blocking diode on the reverse line so that you don't backfeed the reverse lights.

Nice idea!
I find it very handy to have the power switch for the camera and monitor within reach while driving, well worth running a wire or two inside the RV. I hooked up to house power like you would find behind the fridge and the advantage was seeing the fox behind the camper one snowy evening. But power is easily available from the vehicle inside fuse box. Auto stores have a special fuse with another fuse and hookup wire attached so easy to steal a bit of power from any fuse circuit.

Sure you could but depends on the model.