Haunted High (2012) on Netflix

Plot summary

At the private New England school Holloman High, teacher Myers questions student Quentin Smith about his link to a former headmaster, Alger Danforth, a murderer who led a cult. In the basement, artifacts tied to Danforth slip from Quentin's hands and knock open a time capsule sealed in the 1950s, releasing the ghost of Danforth and his assistant. The rest of the school knows nothing. Ortiz, the janitor, hears of the escape and is locked in a closet by Danforth's henchwoman; he has spent decades investigating Danforth's cult. Quentin gets away and asks seven friends for help while Danforth and his assistant turn their powers on the group.