JCT05

This movie is quite old, I saw it about 25+ years ago in 3rd grade. It was about a young boy who lost his hair, because he got spooked after peeping in an abandoned building. Two homeless ghosts (I think they were ghosts) gave him a recipe to mix up and put on his head to make the hair grow, but the hair would not stop growing, it grew by the second. Then the boy was kidnapped by an artist who wanted his hair to make paintbrushes. That is how they found the boy at the end, because his sister saw some of the brushes in a store and knew it was made from her brother's hair. Can anyone help me out?