A 'Trigger object' is placed in a paranormally active room in a certain position
or if possible placed on a piece of paper which is then drawn around so that any
movement can be observed throughout the investigation (dusting the object with
flour is also another way of doing this). It then acts as a focal point to try and encourage activity between the spirit energy and the selected object.
Trigger objects are often used in the paranormal field and can be almost anything.
An investigation team will choose an item that is linked in someway to the reported activity of the location. An example would be if it were a religious building, a 'Crucifix' maybe used. Or if a room has had reported sightings of spirit children playing, an item such as a toy might be used.
Normally a locked off video camera would be placed watching it to record the
events if they should happen, and quite otten the door is locked with no members
of the team present in the room as a good control measure. Sometimes
other devises such as movement detectors, audio recording equipment and temperature sensors are also used to monitor the object/s and the room.