Paranormal EMF Detectors

Here is a skeptic about electromagnetic detectors used to detect unexplained fields at paranormal vortexes or supposed haunted houses, etc. 
They detect any electromagnetic fields. But when it comes to trees rocks and soil there should not be any EMF. This is used in the field. And since my understanding of paranormal events are caused by electromagnetic holograms it is possible to indicate something is strange at that location.

https://skepticalinquirer.org/exclusive/ghost-meters-i-can-name-that-ghost-in-5-milligauss/?%2Fspecialarticles%2Fshow%2Fghost-meters-i-can-name-that-ghost-in-5-milligauss%2F