Telecaster copy suddenly humming

Hi
After a couple of years with now complaints about my guitar, it is suddenly humming quite loudly through the epi valve jr.
I have switched the cable, and the amp, with no change in the hum.
It gets worse when you aren't touching something metal in the guitar.
Any Idea what it could be?
Thanks

Hi Jeffrey, It sounds as though the earth to the bridge (Or Vol Pot) is somehow not functioning (Dry Joint) or whatever (Re-soldser is easy) Does the hum get less if you touch the strings.? There are other factors quite different but try this first get a short piece of wire and attach a crocodile clip on one end and clip it to a part of the bridge and wrap bare wire from the other end around your little finger...(No danger involved)
Let me know if it basically eliminates it.

Fenderphil