No such thing really exists. If cleaning up the wire ends and putting new lights on didn't fix the problem, it's probably a ground issue. I seem to recall there are ground connections to the frame in a couple different spots, one toward the back usually and another I think near the junction box on the back side of the header frame is where your battery wires go to. Make sure those grounds are clean and contacting good.
Hopefully someone can confirm or deny this. I just vaguely recall those there, but I've never personally had an issue with them. The factory lights that came on your trailer were horrible for leaking, so usually putting new light fixtures on solves the problem for most people.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR