I had this happen. Disconnect the electrical connection. Spray Electronic cleaner I use CRC 11 oz cleaner from Harbor Freight SKU: 62228. Let dry re-apply. Put together. It worked for 2 days. I reapplied the cleaner and it has been fine since. If that doesn't work, replace switch, I have a few for sale if needed. If you get you own, make sure the plug is correct.