Yes, it can be disassembled and cleaned, need to use contact cleaner AND Lube in spray can on it. It could be shorting out if metal tang of switch is hitting the side of the aluminum switch housing. Cleaner alone will accelerate wear on the contacts. A small tin of contact grease is ideal as it helps control oxidation and arcing of contacts and helps them operate smoothly. WD40 is a great wire drier but poor lube and it will wash away any contact grease that might have been present.
Disassemble it inside a big clear plastic bag. One you can have both hands and tools inside so anything that pops out or falls out doesn't hit the shop or floor BlackHole where they are never seen again.
May need strong desk/bench light to see more clearly. Never hurts to have a magnifying visor or magnifying glass to work on things like this.
An electronics store or online supplier carries the spray cans and the grease, or Amazon or EvilBay.
Sohron has an excellent article about rebuilding left hand control. Look up his profile and then look at posts and then sort by topics and page through to find. I am on an ancient tablet that is crippled from doing much other than some posting and reading.
Good luck, David
Use "site:forums.sohc4.net" in a Google search
PS google search lefthand or left-hand control
