A phantom is bothering us, what should I do?

I am an owner of the small wool-combing business in the quarter of San Brancazio, and in my spare time I sing in church, in Santa Maria Novella, and I am their leading captain. I am a devoted Christian. I am married, my wife, Tessa, is a daughter of Mannuccio dalla Cuculia, she is very pretty and smart. We have a country house at at Camerata, where we live when the weather is good. I come there after work and after the church singing, to eat and sleep and go back to my business workshop in the morning. Today I came home really late. My wife and I had our supper, boiled salted pork, and went to sleep. After a while, someone started softly knocking at our door. I woke my wife. She told me that she had heard this knocking for several days, and she thought that it was a phantom (or some other poltergeist) because though there were knocks, there was no one outside. She said that she was very scared, but I told her, that before going to bed, I said the Te Lucis and the Intemerata, and crossed the bed from side to side, so we had nothing to fear. But my wife said that we must exorcise this phantom, and that she knew how. I am not sure we should do it. First, because I am Christian, second, because God knows what may happen. But my wife insists and won't go to sleep. What should I do?