Les Paul Grounding

[dabhoys]

I'm having a problem with my 1980 Gibson Les Paul Custom. I was getting buzzing from it and I've discovered the ground is not to be seen anywhere. I assumed it should be coming from the bridge to pots but there is nothing coming from the bridge? Is there any other possible way to ground a Les Paul. I don't want to start drilling into my guitar.

Would appreciate the help...

Cheers