Try working the switch a couple hundred times. Contacts might be dusty; maybe... Next step is to spray some decent Contact Cleaner into the switch openings in the case, which means removal from the pickguard or top.

There are some plug/play pickup sets, but most replacements will involve soldering. Take pix of the switch or draw a wire-color diagram if need to replace. Might also find a loose solder which is why you have the glitch. use a 15 to 25w solder gun, no need for much heat...

While at it, also check your output jack.

Fender type "wheel" selectors will easily get dirty. Lots of crap left in guitar bodies from routing. Inspect everything. Probably just needs a good spray w/contact cleaner and working the switch few hundred times to clean the contacts.

Be sure to use correct screwdriver(s) and protect your finish from accidental scratches. good Luck~!