Ground or float pedal sockets

urban_winter

I'm trying to build a midi-controlled effects loop switcher - i.e. in/out/send/receive sockets - In is connected to either Out or Send, Out to either In or Receive, switched by a MIDI message. Question is whether I should wire all the sockets to the pedal PSU ground or just connect them all together and allow them to float wrt to the pedal circuit? I initially thought that I would wire them to ground, but I don't think it's necessary. 

U.

normula1

With the ones I've built I had to ground the audio input of the switcher to get rid of noise. I don't recall grounding any of the MIDI connections (I built in a MIDI thru and merge)