How to pull off this practical joke??

Hello all. I want to do a practical joke on my wife. We both speak Spanish but not Italian. I want to (in the middle of the night while she�s sleeping) start making exorcist noises and start saying some phrases in Italian, which she knows I don�t speak. What could I say in Italian, that would be ociated with an exorcism and how would I pull the joke off? Also, when she starts freaking out, and I start laughing...would you dump me or would you think it was really funny?