To control a ghost, enter the tutorial house and continue until Betty enters. Put in a series of fireplaces (burn to death) or light bulbs (electrocution) and move Bob out of the house. Block all the exits and kill Betty. The game will announce that you failed the tutorial and Betty's head will still be on the control panel. Click it and her ghost will appear. If one action is done, or you wait too long, she will disappear (you can get her back). Try changing her clothes and taking baths. Note: This may not work in the patched version of the game.