Bringing lazy to a whole new level
This is a metal conduit wiring method, where the metal pipe carries the ground for you. Easy peasy! But this person was so lazy they couldn’t even be bothered bringing a neutral wire.
Not bootlegging ground, bootlegging neutral.
They just left off the neutral wire. Neutral is jumped to ground to steal neutral from the grounded pipe.
Now, I work enough with EMT to know the pipe does separate from time to time. Under this disastrous miswiring, when this happens it will energize the pipe with 120V along with all equipment chassis, junction box, cover plate screw, etc.
Just throw a neutral wire in the pipe
All you need to do is throw a neutral wire in the pipe. And remove that jumper.
And you'll probably need to do this on every recep, lamp, disposal, and every other 120V load on the premises.