Newbie question about 3pdt

[fuzzfarmer]

So i attemped the true bypass on the Big muff Pi. Sounds good when the pedal isnt switched on.

Sounds good when its on, maybe a little hum, and the whole guitar and cable are microphonic? you can tap on the guitar or the cord leading to the pedal and its like your tapping on the pickup.

Input and output jacks seemed to be grounded.

[Processaurus]

Are you saying it didn't do that before you changed the switch?

[jeroen_verbeeck]

If it didn't do that before you should tripple check your grounding wires.