The House in Nightmare Park- ( comedy horror / mystery) - 1973

comedy horror, nod to the films of Hammer and Amicus..
A struggling (hams it up) actor, Foster Twelvetrees, is invited to perform a dramatic reading at an isolated country house, and becomes involved with the sinister intentions, of the weird and greedy family as they fight over a will.
Bodies start to pile up ,and Foster, comes to believe someone is trying to kill him as well