This is one of my FAVORITE episodes, and I've managed to find out most of what the black and white movie clips are, except for one bunch:
Okay, the ones with the man's face in the paintain, and the people disappearing as the wall opens up, and the guy bumping the organ behind him to open the walls, is the East Side Kids and Bela Lugosi's 1943 movie Ghosts on the Loose
Rowlf's scary guy with mean eyes is Bela Lugosi from 1932's White Zombie
Now here's where I'm stumped, there are other clips with people being chased by men in white sheets with pointed tops and faces painted on them. Does anybody know what movie that came from?