Auxiliary lights wired to cargo light circuit

[Camy13588]

So as the title says, I wanna wire aux reverse lights into the cargo light circuit on my 2015 SLT Sierra. I’d like to mount them on the bottom of my trailer hitch. I’ve been looking on other forum posts and can’t really find a direct anwser. Is there a factory wire in the spare tire area that is a part of the cargo light circuit? Or where could I splice into the cargo light circuit. Thanks 

[mpg0101]

Back by the spare tire, Drivers side there is an electrical junction bar that holds multiple plugs. If you don't already have cargo lights in the bed the plug to the far right/passenger side will have a dummy plug in it. You can remove that and use it for what you want, and it will be controlled by your cargo lamp switch in the cab.

[jpinoy]

should be able to give you the location..