The compass is a useful instrument to an investigator due to its compact size and low-cost price. When used on an investigation, this will indicate spirit presence when the needle cannot come to a precise heading or spins/moves erratically.
For best results, here are some guidelines for using a compass in “haunted” locations or during ghost hunts.
Try to use only compasses with free-swinging needles. If the needle tends to get stuck pointing in one direction, it’s not helpful. Before you start, line up North so the red part (or point) of the needle is over the arrow painted on the compass. Your backyard is a good place to first learn how to use the compass in a “not” haunted area. Just make sure there are no electrical wires underground and overhead.
The first time you try using your compass, walk in as straight a line as possible, directly towards North or South. Expect the needle to bob and bounce as you walk. This is normal, however, when you pause, it should always return to North. Try to keep the compass as flat as possible. If you hold it at an angle, you may be holding the compass wrong and the needle may become stuck. If North seems to move, pause, and check how you’re holding the compass, and remember that North will NEVER change direction. Look for interference from magnetic deposits and from electrical sources, like power lines, to debunk odd readings. Magnetic deposits and electrical sources will “attract” the compass’ needle.
Always keep in mind that North NEVER changes its location. Even a slight 10° shift is an anomaly IF you have eliminated all other influences. Profoundly haunted sites can show unexplainable needle swings up to 90°. If you think you have an anomaly, retrace your steps to see if the compass anomaly repeats. If it does, check again on another day. Unfortunately, for documentation purposes, a genuine haunting is unlikely to repeat the compass anomalies in the same places day after day. If the anomaly does repeat, there is more than likely an electrical or magnetic interference with the compass’ action.