[Jagman]

I just bought a used Bill Lawrence SwampKaster S (strat). It looks great and sounds fantastic! Except that it has a grounding buzz. Sometimes it goes away when I touch a string. If I touch the screws that hold the 5 way pickup switch, it will get louder then quiet, if I keep touching it. I'm kinda new at this so....Is there anything I can do to prevent it, or do I have to take it in to the shop?

Thanks,
Jagman