Sounds like 'Clue'
Read the description. It sounds an awful lot like the movie 'Clue' (1985). Unrelated people go to a mansion where a butler is expecting them and knows their names. They start getting murdered. I'm tired. Bye.
share...and 'Clue' sounds an awful lot like "And Then There Were None", the 1939 Agatha Christie novel that inspired it, which also inspired 'Gumnaam' and dozens of other mystery/thrillers/spoofs.