Back-up switch location

I just got my truck (2006 automatic 4x4 v6 4.0L) back from the shop after six months and the back-up light doesn’t work.
I checked the fuses and they look fine, and I can’t for the life of me find the location of the back-up light switch.
Does anyone know where to find it?
Thank you!

 

It’s on the transmission.
Looks like this.

I’d check for power and ground at the tail light first.
Because the nut on the PNS Switch can be hard to remove.

 

As TnShooter stated above the backup signal on an automatic transmission comes from this Park Neutral Safety Switch. On a Manual transmission there is a dedicated microswitch that screws into the transmission.

The Park Neutral Safety Switch can be a bear to remove esp if you live in a salt state.

 

Mine is a manual 5-speed, I hate auto, my first car was a 55 VW in 1960 So it is it on the driver's side? My truck is a 1996, .4 regular body this is it with the bed off getting the frame fixed that is the nice guy who fixed the frame the jerk I bought the truck from missed the recall by 6 weeks it was only 82k on it it took 10 years to eat the frame it's fixed now I checked all the fuses under the hood and dash I did pull off one light jumped 12 volts to the light from the battery it then lite both back up lights which makes sense I'm 82 now a bit scare to get to far under it but I do have younger pals but they don't know were it is one is a retired mech I hope that is not a left hand thread LOL