That was my original idea, but it was coming down to the wire because I wanted it for Christmas, and after checking e-bay, craigslist, all the thrift stores, and begging friends and family to check their attics and basements, I couldn't find one. I had sold the girls Barbie house years ago in a yard sale, because neither of my girls ever really liked Barbie, so it was just in the way.
DH is pretty handy (thank goodness), so I just had him build it, because we were quickly running out of time.
And the movie posters I found online and printed out. I just googled vintage Movie posters and inserted the theme I needed like ghost, frankenstein, vampire, mummy, ect.
good luck on making your Monster High house!