MPC Hum

I have a serious hum in my MPC tracks when I track them into Pro Tools...Is there a special wire that I need to ground the MPC? Also what do I ground it to? I didnt have this problem so much before but ever since I moved into my new spot where I live at now my MPC has a horrible hum and my Motif is humming too...Did I manage to damage these instruments while moving? Also, they are plugged directly into the wall...should I get a surge protector maybe to cut down on voltage? This is irritating me because I didnt have this problem before...