swapped pickups, strange buzz

[gearhed289]

I hope this is the right place to post this, especially since it's not a Ric....

I'm getting ready to sell off my non-rev Thunderbird clone, so I removed the Gibson pickup I had put on it, and re-installed the original Artec. Simple - 2 wires, out with one, in with the other. But, now when I touch the (chrome plated) pickup, I get buzzing through the amp. Ground wire is OK, and no buzz when I touch the strings or bridge, only the pickup. I seem to recall this happening once several years ago, and I don't remember if it was a bad solder joint, bad pot, or what??? Help?