If it's been getting cracklier till it expired then it sounds as if it might be the pots needing replaced (or lubed - or, as above, the jack socket) . Not a difficult thing to do for someone with experience in hollow bodies. They are, however, much trickier to work on than solids as you have to do everything through the 'F' holes. There's loads of little tricks to stop everything being lost & tying off each pot to bring it back through the correct holes etc.
If you intend getting into self-repairs, get a copy of 'Guitar Player Repair Guide - How to Set Up, Maintain and Repair Electrics and Acoustics' by Dan Erlewine, ISBN 0-87930-291-7 published by Backbeat Books.
Everything *anyone* needs to know is in there.
G.