This is an easy "Haunted Mansion-like" show you can have for your friends.
My cousin and I used to always make haunted house shows for our families if we spent the night at
our Grandma's. All
you need you can find at any hobby shop, your local hardware store and around the house.
Large sheet of glass or transparent plastic
I order to make a ghost appear in your house for halloween or for some other reason just use the example of how Disney does the ballroom scene on the haunted house ride. The way the scene works is your car is up at about mid height of the ballroom. There is a pane of glass between you and the action. The room you are in is completely dark. The ball room is lit on the other side of the glass. This way you can see through it. This is like being able to see into a lit house at night but only seeing a reflection from inside the house. Then on your side of the glass above and below you on the ride the "ghosts" are regular disney animatronics. Then by lowering and raising the lights on the "ghosts" you see a partial reflection of the ghosts but can still see through them. You can do the same thing by getting a large piece of glass that can block the main hallway to your house. Place the glass at such an angle that the reflection from the door view goes to a room where you can set up your ghost. Keep the ghost dark until you want it to appear then raise the light on it and it will appear as it should.
Well, hope you have fun! BE SURE IT IS NIGHT WHEN YOU DO THE SHOW!