Hi Dom, "The Haunting of Collinwood" is some kind of compilation of scenes from the Quentin haunting of Collinwood storyline as aired from late 1968 through early 1969. I think MPI periodically issues this kind of thing as a kind of "gateway drug" for people interested in the show who may get bogged down if they try watching from either episode 1 or from Barnabas being released from his coffin. At least I presume that is the rationale behind these.
xo G.