When a haunting is active, witnesses may report observing something
moving - it could be one or multiple items. But if there is one item
that seems central to the odd activity, then that is a 'trigger object'
of that particular case.
It is also a common practice to use items during investigations to see if a 'trigger object' can be found - something that will cause an active spirit to respond to paranormal investigators, proving the presence of an intelligent, invisible entity.
Let's understand a bit better the area you are investigating by attempting to piece some of the facts and gain an understanding. If you can develop a theory based upon the story and any evidence, it is possible to test the idea.
The object of choice should be chosen to have the best chance at making an emotional connection with the lost spirit.
There are two ways to use the trigger object:
The use of other equipment such as EMF meters and movement detectors that light up but not make a sound are also useful tools.
Try and match your trigger object with the facts of the case. (Be
sure and not select something for your experiment that can move on its
own such as a ball.) If a child spirit is believed to be there, then
choose a toy. If an old man, then use one of his possessions. If you do
not know how to tie the trigger object to the spirit, then why not try
using something colorful and out of place to spark some reaction? The
point is to use some logic behind your choice in order to gain the best
chance at triggering your ghost into action. You are trying to connect
with a spirit's emotions.
Some suggested trigger objects: jewelry, coins, non-electrical toys (e.g. stuffed animal), a watch, clothing, a book, a pipe, religious or wartime objects, photos etc.