HID Conversion issues!?!?!?!

So yesterday i went to connect my new HID lights for the headlights and when i tested them out they were working fine....then when i turned off the headlight switch it started buzzing from the switch....could it be bad wiring or the headlight switch going out?????

I'd start the checking with the hot lead then go to the ground wire, and work through the wiring from that point. sounds like time for the multi meter.