Use a Compass as an EMF Detector

You don't need to spend a lot of money on fancy ghost hunting equipment.

For instance, you can use a compass as an EMF detector. Compasses are cheap, but do make sure you get a quality compass that will work if off-balance or shaken.

EMF levels pull the compass needle away from magnetic true north. If it deviates more than 30 degrees, that usually indicates a "hot spot". In other words, when a ghost is near, the needle spins and can't find north.

Note: Do make sure to rule out the possibility of an electrical source, and know which direction north is. Also, learn to use the compass in a location that is not haunted first, and avoid power lines (both overhead and underground).

You may even want to consider getting a digital compass to work in conjunction with the traditional version, because digital detection is not the same as traditional magnetic.