I have now done this twice on trailers Both Jayco's
I purchased Wired color night vision camera's off ebay for cheap.. $25.00 each
I also purchased a 7 inch TFT rear view mirror display about 45.00
I leave it on going down the road
Just glance at the rear view mirror and you are looking out the back
I wired it from back to Front of trailer with Coax cable and RF to Coax adapter.
HD has the coax cable RG6 and the RF to Coax adapter. Get enough cable to make the whole run to the rear of Truck and from Rear of trailer to tongue plus a foot or so for tie in. Used a coax slip on connector at the bumper between Truck and Trailer connection
Powered the camera off the running lights
Ran the coax from the bumper up into the truck cab
Found power in the overhead from the courtesy lights
No interference on the camera signal at all.
Downside of the camera is they do bleach out if the sun is shining right into the lenses but for under $100 investment it works so well!
Problem with wireless camera setup is limited distance they will transmit as they normally run in the same Frequency as Bluetooth devices and same specs on the power they can use to broadcast the signal.
So if you have your phone BT connected for hands free in your vehicle you can and will get interference or from other vehicles on the road.