damn i love me some ghost stories. op should really invest in a camera. purchase new balloons, set them in the living room and put cameras there and all bedrooms and bathrooms.
Don't listen to @B-Bob - he's in the pocket of Big Science; that's how he makes his day to day living. It was definitely ghosts. More interesting part about all of this is tying a balloon to a 3 month old. Intriguing idea. Not sure if it would work for us because our jack russell would probably try to attack the balloon connected to the baby, but maybe I could tie something else.