50mm away? So, 50mm of your finger gets exposed every time you turn the light off... seems a rather low dosage over time to me.

I get the same feeling travelling transversely under power lines or over running water. This does not happen when I am stationary or travelling parallel to either.

I have heard some people say that devining water or electical power is hogwash but I have done it as a resident engineer on many construction projects. I was never without my divining rods when I travelled to remote sites... try to find a suitable tree in northern or coastal Labrador from which to cut a divining stick(s).