Being an electrician as well and working with meters all the time, I treat them like gold and make sure the stay calibrated. I too use a K II on investigations, but like and meter it should be calibrated. How and where can this be done to verify accuracy. I have experienced this before, but unless we capture other things as an evp to go with it, we chaulk it up as nothing or a fluke, but not claim it to be anything really. even new electronic meters can get out of calibration in shipping. Problem is we are dealing with a fringe science and therefore our equipment are not required to follow the same guidelines as true science. long answer, huh?? Hope this helped!!