Polish tradition: Blessing a new house
Before a person or a family moves into a new house, the Priest blesses the house and draws a cross above the front door of the house.
Bruce said he learned this tradition from his Polish family and relatives. His family and relatives moved to the United States (he grew up in Bridgewater, Massachusetts) in the 1920s when he was a very young child, but he said that he learned this tradition from his Polish family and knew that it came from Poland, not from the United States. As his family moved houses in the U.S., a Priest would always come over to the new house, bless it, and draw a cross over the front door. This was a sign of faith, as by doing this his family hoped God would watch over their house and keep them safe.
Bruce did not mention if the blessing is supposed to draw out evil spirits, but the blessing is supposed to make the house pure and fit to live in. Since evil spirits are not pure, then it makes sense that driving evil spirits out of the house is part of the blessing. Also, I am not sure if this is a purely Polish custom, or if it is a Catholic custom found throughout the world. Bruce said that Poland used to be controlled by the Catholic Church, and Poland used to be 100% Catholic, so it is possible that the church brought this tradition to Poland from elsewhere.
I have heard of various forms of this tradition, including one belonging to my family. We (my family is Catholic) have a similar tradition except we bless our own house with Holy Water the Priest distributes at Mass every year. It is a sign of cleansing, renewal, and asking God to keep us safe throughout the coming year. This similar tradition leads me to believe that the Catholics, not the Polish people, inspired Bruces Polish tradition.