Stacey and the Mystery at the Empty House

Bonjour! Charlotte and her family are of to France! Stacey was asked to watch their house and Carrot, their dog, while their gone. Of course, she agrees. But, during the first couple of days she starts to notice some strange things going on. Carrot has been growling, there are random glasses of water that she hasn't used, and one of the hair brushes has orange hair on it! Is it possible that someone is living in the house?