A Cheap and Effective Alternative to K-2 Meters
K-2 Meters are expensive and may not fit into every ghost hunter's budget. A simple and effective way to determine if there is an EMF field present is a compass. If you are moving through a magnetic field, the compass should deflect away from magnetic north. The speed of the compass rotation can give you an idea of field strength. If the compass is stationary and a magnetic field moves past, the compass should deflect and give you a sense of field strength and the direction the field is moving.
I prefer a compass that doesn't have any fluid inside. In my experience, a stationary magnetic field generated by a spirit will cause the compass needle to vibrate or shake. If a compass has fluid, this will dampen needle vibration. Another advantage a compass has over a K-2 Meter is that it's less likely to be affected by alternating magnetic fields like those generated by AC current or cell phone signals. K-2 Meters are designed to operate over a frequency range. All electrical wiring, radios, televisions, cell phones, internet hotspots, and cordless phones operate in a frequency range that can be detected by a K-2 Meter. In comparison, a compass is not going to be affected by these frequency ranges.
You can purchase a good compass with glow in the dark face at Walmart for about $5 or order a military-grade compass from Amazon for under $50. Either way, you'll no longer be plagued by the never ending question of whether it was a rogue cell phone signal or an actual spirit that caused that EMF field you detected.