Reverse light switch location?

I am trying to hookup a rear backup camera. I tied into the backup lights to power the camera and it works fine on my radio lcd screen when I manually go to the camera screen. However, I would like to cause the screen to switch automatically when I put the car into reverse. To do this I need to hook up the radio's "reverse" wire to the backup light power as well. I don't want to run another 15 feet of wire to the trunk to pickup this line. Is this wire available anywhere UNDER the dash or near the FUSE panel? I've searched the internet for camry wiring diagrams and gave up. Thank you for your help.

Thank you, I will look for the red/black wire to the left of the steering column. I will post my findings.

On my camry when I put my car in reverse I was told neither lights are coming on even the plates lights are not coming on change bulbs and still noting

where will I find the switch. I already check fuses & bulbs. When I took of the license plate lights it came on for a little bit then noting after. And it seems the wires are all tape together for the reverse and license plate lights is that correct.

This is my wife's car so I do not know how long they have been out. 4cly, 5spd stick 40,000 miles original owner. All lights work except for the reverse lights - bulbs are not broken, cannot find a blown fuse but perhaps I am not looking in the correct place. Thanks for your help, M.E.