I just installed a JB with an on/on/on switch and there is a slight hum. the hum is higher pitched and not as loud as the hum from my single coil. My rails has no hum and when i split the jb combined w/ my single coil there is no hum. What do u guys think is the problem? Everything is grounded. Although my soldering is ify, lol. Anyway, please help!