I've just remembered one other little incident which was on a TV documentary a few years ago.
A family living with HV lines running near the back of their property were concerned about the EM fields (I can't remember the voltage levels, but must have been 132kV or above).
Field strength readings around the house didn't show anything out of the ordinary, except when they reached the head of one of the kid's beds when the strength shot up.
It turned out that the meter was located right on the opposite side of the wall.
