Nice fact rdavey! I had also heard that the scene of Heather O'Rourke holding on to the bed and screaming when the closet is sucking everything in is the only take. She was so terrified that Steven Spielberg promised that she would never have to do that again so what we see on screen is her being genuinely terrified of the stunt and everything going on all around her.
So, yes, the film - Poltergeist (1982)
The poster in question, there are two - obviously the Star Wars Style A folded one sheet but also the Alien poster by the closet door (thinking it's a commercial poster).
The eerie poster fact is Robbie has a poster in his room for Superbowl XXII (you can see it in the night shot below next to Star wars), which would not take place for another six years and Heather O'Rourke died the day after Superbowl Sunday of 1988 of intestinal issues.