Trigger objects can be almost any object, placed into a locked or empty room which apparently attracts paranormal activity.  Commonly, the object will be either outlined on top of a piece of paper or placed into flour or powder as a way to measure movement when there is nobody else in the room.  

Investigative teams are likely to use objects from the room which have a history of being moved by unseen forces, or religious items such as crucifixes in an attempt to attract the spirit’s attention into moving the object.  Although the teams have no idea yet where they are going, it’s fairly certain they’ll have plenty of artefacts with potentially gruesome pasts that will make ideal trigger objects.