I guess the part about all of this that is most amazing to me is that the electrician who wired the upstairs ran the white wire (from downstairs) to the neutral bar (upstairs), which is correct, BUT THEN he attached all the black wires to that same neutral bar I would think common sense would tell him not to mix white wires and black wires to the same place, but he obviously ignored that fact The biggest problem I'm seeing with everything now is that the sub-panel upstairs isn't grounded. At first I thought the metal jacket of the wire was picking up the ground from downstairs, but then I noticed that the metal jacket ISN'T connected to the downstairs box (it's just run through a hole in the main panel).
Upstairs, all of the grounds are connected to the sub-panel grounding posts, BUT the sub-panel is just nailed to the stud and not grounded anywhere. I'm not sure how the system upstairs is being grounded but my tester does show each outlet as being grounded. Maybe they used the outlet in the bathroom to ground to the plumbing? Not sure but I would feel much better if everything was getting its ground straight from the sub-panel. Can I use the metal jacket as a ground by connecting it to the panels (upstairs and downstairs)? If not and if I have to run a wire, then it would be easier to run the wire outside. Can I use a grounding pole for this? If so, then what gauge wire would I need to run?