Just another comment, not an argument.
Have rewired several machines myself, making positive sure there is no shorts. Have bought other machines with good wiring and inspected them finding no shorts.
Have been buzzed by some of them. Turned the cord and the problem ceased. There are times you'll get a buzz from machines with good wiring.
If you are afraid of the buzz use the back of your hand or your wrist to check the machine. That way your muscles in your hand cannot contract causing you to grab the object if there really is a short circuit.