switching refinement

[turing]

ok, not wholly pedal based, but the principle is the same (i think).
i'm making a switch for the talkback mic in my studio, very simple, just a push to make spst to complete the live or neutral mic signal. the other signal wire, and the earth are linked from socket to socket.
trouble is, there's some hum when the switch is open. i poked an earth wire around, and when i tied it to the switch socket it improved but didn't kill the buzz completely.
can anyone suggest some kind of cap placement that would knock it out altogether? or even a different approach?
many thanks

[Pushtone]

No matter what I seem to be thinking about there is someone else thinking the same thing on this forum.

Different approach...

This would do it for ya if you don't feel like trouble shooting your box.
http://www.radialeng.com/re-hotshot-dm1.htm

Or perhaps you could install a ground lift switch in your box.

[turing]

aaaaahhhh, got it. found a schem at pro sound web. simple little circuit for condensors, with pop reducing caps etc.