I recently redid a room in my house (older home built in the 60's i believe). I decided to replace the outlets as well as they where loose and wouldn't hold plugs very well. When i pulled a few of the old outlets i found what i looked up to be called "bootleg grounds" on two of the three i replaced. I installed the new plugs without the jumper as they appear to be in conduit boxes and i read the jumper was a really bad idea. I looked up how to test these outlets to be sure the ground is there. (i have a nice fluke multi-meter) When i tested between the two slots i get 120v as expected, now hears where it gets weird and you have to forgive me as im a novice with electricity. when i tested from one slot to the ground hole i also got 120v which i believe is the hot to the ground so that should be expect as well, but when i switch to the other slot to the ground hole i get 220v, which i believe is a big problem, what i want to know is what could be the cause of this so i can try to start hunting this down. Could it be other outlets down the circuit with bootleg grounds causing the voltage to double essentially acting like a 220 circuit? I'm going to start looking for other outlets with the bootleg grounds but i wanted to get more info on this at the same time. Any and all help would be greatly appreciated.

EDIT: I ran around and tested a few more outlets some I'm getting 330 volts at and other 500+ volts..

  • Something is very not right here -- does this occur for all outlets in the house, or just some? Sep 18, 2016 at 22:48
  • it appears to be all of them, i just went and tested the kitchen and the bathroom, im getting 330 in the bathroom and 500 something in the kitchen...
    – bmenke
    Sep 18, 2016 at 22:57
  • blinks What sort of meter are you using for this? I suspect that something is hideously awry with it... Sep 18, 2016 at 23:05
  • 1
    Are you sure you're really seeing 500 v, and not 500 millivolts? Those meters can automatically switch scales.
    – Mark
    Sep 18, 2016 at 23:06
  • Voltage over 250V should not be present anywhere in a home. On a 3-prong outlet, one slot is slightly taller, that is neutral and should be quite close to ground, certainly within 3 volts and commonly within 1 volt. Sep 18, 2016 at 23:07

1 Answer 1


Are you sure you're really seeing 500 v, and not 500 millivolts? Those meters can automatically switch scales. – Mark 6 mins ago OMG this was it... im kicking myself now. Everything looks ok im getting 120 between slots, 120 from one to ground and like 2 volts from other slot to ground.. THANK YOU GUYS SO MUCH, i was running around thinking my house was going to explode!

  • Glad it helped!
    – Mark
    Sep 20, 2016 at 0:28

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