Symptoms indicates a likely ground circuit fault rather than the moisture.
Lightings share a common ground and there are several points on left and right side for front and rear. When a ground circuit fails, voltage would reverse flow through those lights that are not being operated to get to the next good grounding point available and this would cause them to malfunction.
Check all lighting grounding point to ensure they are clean and secure.
Saturday, February 9th, 2019 AT 8:21 PM