Durring the run of a show today our hanging mic a Sure MX202 Microflex Overhead microphone started buzzing. All of a sudden it just started buzzing at -20 db lvl on the board. No build up to the buzz or anything, just all of a sudden in the middle of the show it was there. Durring intermission I unplugged it and plugged it back in and that stopped the buzzing. Buzz then returned in the middle of the next act even louder... Anyone know what might have caused this? And how to fix it?