Long shot... what is this mystery cable?

I'm installing a Redarc brake controller on my 2008 TRD Sport with tow package. This controller has an adjustment dial that fits in one of the poverty button blanks. When I reached up behind a blank to push it out, I found this cable lodged into the back of it. I followed it but within a few inches it gets wrapped up in a bunch of other wires and I can't tell where it goes.

This is the long shot - what is it? I'm guessing the previous owner had a usable switch in that location but at some point removed it and put the blank back. Other than unwrapping the tape covering the harnesses, how can I figure out what it does or goes?








The wire in the foreground with the foam on it is the mystery wire that joins that mass above the fuse box.

 

I'm totally unfamiliar with your generation (I have a 3rd gen), but on my vehicle there are various connectors incorporated into the wiring harnesses that are not connected to anything, they are for features/switches my vehicle is not equipped with from the factory. I would say the previous owner had no idea either.

Perhaps there will come along an experienced, whatever generation your vehicle is, person with the information.