Under Wraps (1997) on Netflix

Plot summary

Marshall is a boy who watches horror movies and lives with his mother, who has a boyfriend named Ted. Marshall does not get along with Ted and misses his father. Amy and Gilbert are his closest friends, though they do not share his taste in films. When word goes around that a body is kept in the basement of the late Mr. Kubat's house, the three of them go in to look. They find an Egyptian mummy, stored there, and when moonlight hits an old amulet the mummy comes to life. He frightens them, then proves gentle and clumsy, and they call him Harold. Bruce, an adult friend who runs a horror shop and knows the occult, tells them Harold must be inside his sarcophagus by midnight on Halloween or he will crumble away.