Quacky and the haunted amusement park

When his dog Puddles becomes the victim of dognappers, Quacky pursues his only clue : the sound of a dog barking in an abandoned amusement park. Third book in the series of middle-reader novels about "Quacky" Quackenbush. His dog is dognapped by someone stealing dogs for ransom, and he and his friends trace the thief to an abandoned amusement park. They think it's haunted because they also hear voices there, and learn that ghosts do not live there but street people who lost their homes. Quacky the Good Samaritan has a plan that helps them all to live together in a house helping an elderly couple.