Yep the light switch. Common fails: dirty, burned out resistor and, loose wiper. On the AD type there is a "circuit" breaker like bit. Those contacts can get burned and dirty as well. Isopropyl based works well. No power when using please, it will burn until dry. Drys fast and cuts oils/grease, no silicone.
https://www.zoro.com/crc-contact-cl...CPnuh5CQ38sCFWveMgod0v0PjA&gclsrc=ds


Steve H