Replacing the cap is cheap and easy. Few bucks for the cap and some time to solder it in. You may want to try that and see if you get tone control back again. Otherwise maybe some other posters have had a similar problem and can relate.
While you're at it you may want to pick up a 250k pot too just in case that's where the problem is coming from. I'm one of those process of elimination guys and most of those components are pretty cheap so swapping out old for new and re-soldering the connections isn't expensive or that complicated. The switch is the most expensive thing in there and even that's only about $15.
The real problem comes when you've checked or replaced it all and it still misbehaves. Then you take it to a priest and have it exorcised and have the archbishop bless it. LOL
CS Nocaster; "Nashcaster"/Nocasters; MP Thinline/P90s; Nashville/Onamacs; CVC/Keystones; Lenti Esquire/ Lion, CV JBass/J45s, CV PBass/P46, Taylor 414ce, Breedlove C250/CMe, Roland Cube 40xl, Roland BC 60/CRex; Bugera v5/"Chemp"; tc BG250 Bass Combo.