Get ready to curl up in the fetal position. This Thursday at midnight, the Castro Theater is hosting a free screening of the film Paranormal Activity, a ghost-filled spook-a-rama in the vein of the Blair Witch Project.  Nothing like a good midnight fright-flick to get the adrenaline pumping. Just think of it as a primer for Halloween.  RSVP here for entry.  Muhahaha!