none of the units have a ground pin (they are only two wire) the mic extension is wired properly but the and there only is a shock when it is used.


Is it 120 VAC?

Most likely there is an INTERNAL FAULT of the Amp or mixer.

Less likely, there might be a short in the cabinet if it is a permanently installed system.


Is it 24 to 48 VDC?

Then "phantom power" may be turned on. Phantom power is DC sent over the audio wiring to power specific types of microphones that use internal amplifiers.