EMF Stands for Electro Magnetic Field,
People say ghosts / spirits are made of EMF and that they can also use
emf's to manifest or do something.
So people use EMF meter, to indicate when a ghost is trying to do something.
However there is a alot of natural man made things which produce EMF, and is best to check your location for natural EMF.
These are the things what we at project-reveal have found to give off EMFS:
Mobile Phones - Turn onto Airplane mode to avoid Faulse EMFS.
Wifi - from Broadband and Phone.
Light Fittings - can give off EMF, its best to check all, if they give off EMF when turned off i would suggest to let the home owner a possible danger..
Plug Sockets - Yet again these shouldnt give off EMF, and if you find some please inform the owner.
Fuse Boxes - These normaly can give off a HIGH emf.. but is pretty normal.
Phone Masses, Always scout your Location for Phone masses, as they could give the ODD , Random EMF.
Hope this explanes abit about EMF.