how do i find a ground wire short in a tail light?

The best tool I have found for this is called a power probe. You can however trace an issue like this with your average probe light. Turn your head lights on and stick the probe into the socket with the other end grounded to bare steel on the body. If the probe lights up then your tail light socket ground is bad. If not continue using the probe to test the wire back till you find the physical problem.

So then my signals and Hazards probably aren't working because my rear tail light socket won't even hold a bulb in it so therefore its grounding it out to where my signals and hazards aren't working that might be my issue because the socket is supposed to hold a bulb mine is where you push in and turn the bulb and it's locked but when you push it in and turn it to lock it it don't lock it pops right back up so that tells me that the housing for the bulb is bad which is probably grounding out and not letting my signals or hazards work let me know what you think appreciate it man