I'm not an electrician, but I'd go for the simplest first and check my ground... depending on what type of unit it is, you might be able to get by with just unscrewing the ground wire in the lamp fixture, dosing it with WD-40 and re-assembling it. I'd do the same up at the connector - the WD-40 part. Good luck.
Michael, Suzy & Arnie Asada (Chihuahua)
'97 Viking Legend 2480
'19 RAM 1500 Laramie 5.7L Hemi