Piezo and standard pup splitter box

[Luke51411]

I talked to a guy that builds electric guitars with standard pups and a piezo pup with a stereo jack, he wants to send the piezo signal to amp A and the other signal to amp B. I think he only needs one on at a time but wants to be able to switch them silently with no noise coming from the inactive amp/pup. Is this more complicated than essentially an A/B switch box?