On my bass I have changed the bridge and one of the pups. The bridge was used as a ground and I thought I reconnected it properly. But when I touch a string a sound comes from my amp kinda like the sound a spark makes. But my fingers aren't on the strings the bass buzzes a little. But when I touch the strings the buzzing stops. Also, if I touch a string with one finger and then touch another without removing the 1st, there is no sound. I've heard similar stories and I think this is a grounding problem. Am I right?