Ive never understood why outlets have 3 holes. The two at the top are the voltage in and voltage out, correct? So why is there a ground if the current already has a way to return to the voltage source through the second hole? Also, i am assuming that power lines have two cables coming from a source, one having the current flow toward the destination and one flowing in the opposite direction on the return journey? If this is correct, then why do you get shocked when you stick a paperclip into just one socket, cause the eletrons still woudnt have a path to flow through, right?