I ghosts do not exist then saying a prayer is unlikely to be a problem. If they do, and you come across them, and they are friendly, then saying a prayer is unlikely to be a problem. If they do and you come across them, and for some inexplicable reason are out to get you and can, then saying a prayer is unlikely to be a problem and could possibly help, as long as there is someone to answer it and opts to help.
I suspect you'll find you didn't need it though.
If you have been on these sorts of hunts before, then surely you have an idea of what scientific stuff you need ? Unsure about bell, book and candle, or even sand and paper. But it all sounds interesting though. Don't scare yourself to death or someone will be hunting you next.



