Swinging Rosary

We were in the dining room eating supper and the rosary that I got from Father Weary, that was placed and hanging on the wall with the picture that has been there for quite sometime, started swinging back and forth. I tapped my cousin on the arm to get her to look at it and when she did, it stopped. I stood there to see if it would do it again and it did a little, but not as much as it did before. It was never bothered before, why now?