Petromax

In the movie Petromax, an ancestral house is up for sale but rumors spread that it's haunted. The owner arranges for four people to stay in the house for a few days to prove there are no ghosts, but they soon realize that the house is indeed haunted by four ghosts who were murdered by the owner's son. As the ghosts try to scare them away, the four friends, who have peculiar habits, begin to intimidate the spirits. The real ghosts then frighten the fake ghosts sent by the owner's cop friend to scare them away. On the third night, the ghosts reveal their true identities as the owner's parents and their adopted children, who were killed by him. They enact their revenge by killing the owner, his cop friend, and his goons. The four friends find a bag of cash in the owner's car and convert the house into a retirement home where they live happily with other old pensioners abandoned by their children.

You can stream Petromax on: Amazon Prime

Some movies that have similar genres and were produced around the same time as Petromax include Nightbitch, The Menu, Ready or Not, Slaughterhouse Rulez, Fresh, Beetlejuice Beetlejuice.