that isn't a big job at all, actually pretty common; you say "rewired" like you gotta run all new, but no, just cut the socket off and borrow a solder gun>>> solder and heat shrink (or at least tape up good)
I do not like butt connectors and definitely not Schtchloks especially for something like a light socket that's outside the cab and exposed to moisture, water splash etc...
yes it could be a grounding issue and "seeking ground" thru either that switch I mention or the headlite switch..
if that socket is that rotten your problem could be right there.

 

I will be going to my mechanic this afternoon to have this all dealt with.

When the dash lights come on while pressing on the brake, that's it for me. Because that's what I noticed a couple of days ago. My passenger tail light is out completely. Last thing I need is to be pulled over with all these issues.

I'm just hoping that this doesn't break the bank.

 

What you said about the tail light was 90% true. But the wires were confusing to the mechanic working on them. What should have been the ground wire wasn't. But he figured it out, replaced the socket and it worked like new.

As for the system wide failure, the problem wasn't what anyone mentioned. It turns out that there was a short to the tail light from the trailer wiring.

My mechanic shop sent me around the corner to an auto electrician. These guys were on the ball and it cost me less than I thought it would. They even replaced the headlight that had burnt out.

So that problem is solved and everything works properly again.