I'm a videographer by trade so I thought that some might like this idea.
In my line of work we occasionally us a camera crane for our shots so I was thinking that a camera crane would be useful for a flying prop. You can build a crane very easily and not for a lot of money. Go to youtube look up DIY Camera crane and you see how easy they are to build. Now here's how you can use it for a flying prop. On the end of the crane where the camera would be you could change the mount to fit a ghost or whatever you like. Now all you have to do is add enough weights for counter balance and the raise up your prop and move it around like it's flying. Of course you would need to have a long covering so as not to see the crane. Note!! some of these cranes can reach 20 or more feet in height. And one other piece of camera equipment you could make is a camera stabilizer it makes the video look as though it's gliding. Here's my thought what if you used one of these to have a prop like a ghost or skeleton move like it's gliding of course you have to operate it from a distance but think about how cool that would look. I'll try to work out the details on that and get back to you. Anyhow try the crane idea and see what ya think.