Silver Bullet (1985) on Netflix

In the spring of 1976, inhabitants of the peaceful town of Tarker's Mills, rocked by recent, violent murders, press Sheriff Joe Haller to investigate and find those responsible. Meanwhile, crippled boy Marty is very happy with the new motorized wheelchair his dear Uncle Red has given him. One night, Marty sneaks out to a remote bridge to set off some fireworks that Red also gave to him and is attacked by a hairy creature. Luckily, Marty shoots a rocket in to the left eye of the attacker and escapes. He tells his sister Jane he was attacked by a werewolf and convinces her to seek out anyone in town with an injured eye. She discovers that it's the local reverend who is the creature. Now the siblings have to convince Uncle Red to help them prepare for a visit by the reverend at the next full moon.