I bought a old duplex house with 2 wire electric circuits and 3 prong outlets. A home inspection found the outlets had no ground,the seller agreed to having an electrician "rectify" this condition which silly me,I assumed meant running a ground circuit. A 2nd inspection showed the outlets were grounded according to a 3 prong plug in type of outlet analyzer,I buy the place and rent out the upstairs to a gal expecting a baby. After a few weeks she tells me she is getting shocked at her sink when the water is turned on, hum, ok, I go there with my fluke meter and reference from a ground outlet and read no power. I think she is nuts but she says it's still doing it.
I have an electrical contractor come out and he says I have bootleg grounds at each outlet meaning jumpered to the neutral leg to fool a plug in outlet analyzer,they will test normal when no ground exists but even worse was I had reversed polarity meaning my outlets where hot on neutral and on ground and the ground was hot. Since I was referencing from the hot leg thinking it was ground,I never read power cause it was putting both leads on the hot leg and expecting it to read voltage. Upstairs in the rental the garbage disposals metal ring in the bottom of her sink was hot all the time and when the water ran she had both sides of power required to be shocked since the water was grounded. The house has knob n tube wiring,it took 2 electricians 8 hours to sort out each outlet as to what is hot or neutral which I gather was due to how they used to run circuits with knob n tube circuits because the guys had trouble determining hot or not almost as if the outlets were ran in series like 6 volt RV batteries in a 12 volt configuration, nose to tail like circus elephants not paralell like the rungs on a ladder with the ladders side railings the 2 legs of power.
I know that explanation is not technical but it is how I understood it after much reading and consulting technicians, how else can you not tell the side of power unless the outlets were in series with the next outlet? Is this how they ran them?
The safest conclusion was to install a GFI on every outlet and apply the decal stating no ground exists at this outlet. I thought it was fixed and had no more renter getting shocked when recently I was testing a no contact type voltage detector and my refrigerator door was making the stick light up! I had no ground to reference from that I can trust,I was going to put a stake in my yard with a wire ran to it to reference for voltage inside the house, for now I ran my reefer off another outlet that the reefer does not make the stick light up when near the door of the reefer. What should I do to reference from a known ground?run a ground wire to the dirt to see what is hot or not or is there a better way to figure out this outlet.