Back in the early 80s, I remember watching a horror movie on TV, but I can't for the life of me remember what it was called. Here's what I remember: There was a boy that was trying to make one of his sisters think their house was haunted. He would tape record himself walking on gravel and play it back at night for his sister to hear. The boy had a pet iguana, which ended up in grandma's bed, scaring her to death. I think the boy ended up falling off the roof (actually, he was pushed off by the ghost of his dead sister, who actually did haunt the house towards the end of the movie). There's a scene where one of the girls (not the ghost, but the one that the brother was trying to scare) follows her mother up the stairs to her bedroom with a pizza cutter (she's cutting the wall with it). If anyone knows what the hell I'm talking about, please let me know. Thanks.