Humidity and Faders

This possibly has been a discussion in the past but I wasn't able to find info on the topic so...
I'm head of lighting at a 2500cap venue in LA. When we get all levels full (usually on the Insomniac rave nights) I have a major issue with my faders not going to zero. Or, in the case of last night, one of them got to the point where it wouldn't make it down past 38%. This has happened a few times now.
Please note- I am not novice or inexperienced. I have looked into the issue.
First time it happened was a Saturday. I planned on working on the desk on Monday. The issue was not there. I went ahead and replaced the faders anyway. New faders in place everything worked for the less crowded shows of the week but once again- big crowd, lots of dancing people, high humidity and same problem faders not going to zero. And again- Saturday night and worked on desk on Mondy
I popped the faders apart to see if any component of the faders was damaged. No visible issues. Cleaned the strip and restored the faders. I make it a few weeks without issues. Light show schedule. I think we are gold. Then again it happens. Same scenario.
This time I just let it be. Come in Monday and everything is fine again. And then last night it happened once more. I am going to guess when Monday rolls around I will have 100% working faders again.
I've worked in high humidity environments with the Hog line for YEARS. I started running into the issue a few years ago in a club I ran. It wasn't as bad as last night and 1% or 2% ghosting IO can deal with. But 38% and having to dial down my intensity with the encoder really takes away from my show. Not to mention it is pretty annoying in general.
Anyone else running into this issue? Or any insight or tricks? Bueller? Bueller?

Thanks
Peter Brown
The Belasco