Hope you guys might have some clues as to this since I'm not a physics person at all.
Recently, we found that electrical switches in a home had readings on a Sperry 822A EMF meter that were well above the normal readings for the room. This would not be unusual except that the house has not had electricity for many years and is not even connected by outside wiring to the power grid.
Some of the breaker boxes actually showed EMF readings of 4 to 5 mG. When we checked the outside breaker box ground wire it read 14.0 mG and then dropped to 9.9 mG and then went back up.
We're not sure what to make of this. We were wondering if it was possible for the wiring to hold a charge or become magnetized in some way. However, it is not all switches and outlets. Some are what you (rather we) would expect with no power to the house. Others show that EMF is present. BTW: none of the plug outlets showed abnormal EMF.
Any explanations you guys might have as to why this is happening would help us greatly!