Experiments
There are different experiments that can be run during an investigation. One device that was used was the plasma ball. The theory being that when touched, the electrical signals ground towards the appendage and may give visual evidence of a presence if an entity interacted with it.
We often set up objects to act as visuals in front of our DVR cameras. An example is to see if battery drain is a recordable event since many investigators experience equipment problems due to power failure.
The experiment would be to secure meters to the +/- spokes of a battery, record the session during the investigation, and then watch for readout variances. Or we may place children's toys down if a younger ghost is believe to be present to see if they are played with on camera.
Other types of experiments involve recreating the era of the location in an attempt to make the spirits more comfortable to interact with us. This could be done by dressing in clothes from that era or playing music from that culture, etc.
