First off, sorry if this is in the wrong section...
I have my first show coming up in about 4 days. My band is fine and everyone is good to go. The only problem is, we went to a rehearsal space for the first time a few weeks ago (we haven't been a band that long) and the mic at the rehearsal space was shocking me pretty badly when I'd get close to it.

I sing lead vocals and play guitar. While I was playing and singing, as soon as my lips made contact with the mic, I'd get pretty shocked pretty badly. Also, me and my bass player bumped into each other and we both got shocked.

I was using the rehearsal space's gear, which was a pretty old Mesa stack, and a shady-looking PA. The cords on the mics were pretty old and messed up looked too. My Epiphone LP occasionally has issues with the input jack, but I dont think that is relevant. I dont know if I should just chalk it up to the place's equipment, but Im fairly worried that I might get shocked by the mic at my show Friday.

From what info I've gathered, I've heard that the issue may be because either the PA or my guitar/amp isn't grounded properly. If this is true, and my guitar wasn't grounded properly, how would I go about fixing this?

Thanks UG. Once again, if this is in the wrong section, please move it.
Don't trust mic's at practice spaces to be the best and up to scratch, lots of people use them each day.
My "Rig":

Fender American Telecaster
Boss OD-2
EHX Small Clone