Those “Ghost House” blueprints are from Ken Anderson, who wrote several scripts for the Haunted Mansion back in the late 1950s, all of them walk-through concepts until Disney developed the technology and knowledge about capacity and how to move people through faster (aka the omnimover, or Doom Buggy as they are called in the Mansion) 👻Yale Gracey is also the one responsible for the Pepper’s Ghost effect used in the ballroom. Growing up, he had several volumes of The Boy Mechanic that taught him