Booh! (2005)

One day, the weary Count Purée de Carottes comes to Kronkel's real estate office, asking him to find a buyer for his castle as soon as possible. The Count is going crazy because of the harassment of the ghosts that live there. While cleaning up the castle, Jonas, Kronkel's seventeen-year-old son, finds a pair of glasses in the cellar with a very special property: he can see the ghosts with them. These ghosts initially see Jonas as a threat, but eventually they become friends and Jonas becomes an ally in bullying away potential buyers brought in by Kronkel. Each ghost has its own character and carries its own personal past, which sometimes leads to tensions between the ghosts themselves. After all, they often died less heroically than they claim to the others.