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 simple 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 its strength. If the compass is stationary and a magnetic source moves past, the compass should deflect and give you a sense of its strength and direction.
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 inside, this needle vibration may be prevented.
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 phones. 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, meaning that a K-2 Meter will give a positive indication on everything that is electrical or electronic. Whereas a compass is not going to be affected.
A good compass with glow in the dark lettering can be purchased at Wal-Mart for about $5.