Many decades ago, while working at Motorola, one of the engineering workbenches gave me a very slight tingle.
I traced down the reason: The hot wire was interchanged with the ground wire!
As a result, the workbench ground and all the test equipment were continuous at 120VAC.
It had been that way for a long time. By luck there was no other grounded object within reach.
Bertho
Bertho