If you watch these paranormal shows on television it seems that everyone has an opinion on what exactly opens the door between the 2 worlds.There are many different tools for divination out there that are available to anyone. The first that comes to mind is the Ouija board.
In many of these shows that I have seen,it seems that anytime anyone has used the Ouija board there has been a problem. An evil influence has entered into the home.Do not believe everything you see. Anyone who is in the business of divination will know the most important aspect in using any tool is protection. Noone should ever go into anything without surrounding themself with the white light.They will also know that you have the power to allow only positive entities into the space.Secondly any door that is open should be closed when you are finished.
If you are going to claim that tarot cards or Ouija boards are catalysts for opening doors than understand that any sort of "ghost hunting" equipment should be in the same category. Using an emf meter or an ovilus is no different .For that matter neither is anyone who claims they can detect spirit in places. Just because they come from a strict religious background it doesn't make them any different. They are doing the same exact thing. In conclusion once again I say do your research,protect,protec,protect and remember no light shines brighter than that of the living!Namaste!