This is be done by wires or thread-work. I know there are lots of ways to make a ghostly candle levitate using Pepper 's Ghost (Trivia= John Pepper was one of two people that invented the illusion that bears his name. In fact Pepper, had less to do with its invention. His counterpart's name was Henry Dircks). The illusion is great and powerful, but there is always room for levitation that you could actually reach out and touch. However, when using wires, reaching and touching is not recommended unless you're in on the illusion.
What I am envisioning here is a living room scene, very close quarters with separation railings. This gives the guests time to walk past the room, but not get too close. There should be an actor in the room whom interacts with candle but not necessary.
The Floating Candle:
Gusts walk through a living room. This room has a small table with a candle burning and several plates and settings. An actor stands behind the table and motions to the flame. The candle lifts off the table and floats across the room. It moves up and down and side to side. The actor can interact with it (in magic this means using hoops, but you have no time for this. instead your actor can chase the candle as it evades him on its way back to the table.).
Fortunately, this secret is not too difficult to build. The candle can either be real or fake, but it needs to have a tunnel running through it. If you use a real candle, the tunnel needs to be made of a cut drinking straw.
The tread you use needs to either be thick black sewing thread, invisible sewing thread, or thin flat fishing string.
There will be two uprights in the room disguised so no one can see them. They will look like a part of the room. If you can't get them to hide well enough, you can hide them behind the walls and cut long slits in them.
There are two methods for getting this to work. The first is actor controlled. If you have actors to waste on this, it could be fun and worked into a good scare. The second, is motor controlled. This would be the preferred method by magician's with large scale shows. I would also recommend it for this use. The motors give you a repeat flight pattern and nearly ever mess up.
So if you look over the drawing below from my black book of Halloween goodness you'll see that the uprights have guides that slide up and down (in magic these are much different). The guides are controlled by strings attached to a motor. running through this guide is another string that runs from an additional motor, through the guide, and to the candle. (if the candle is to be controlled by one person or by two motors on the same side of the room, then this string should run through the candle (using the drilled hole/tunnel) and then tied to the other side of the room somewhere near the ceiling.
(I don't blame you, it's confusing me as I write it...)
The motors need to be programmed well enough to have a slow and simple flight pattern that resets back to the table.
That's the basics of the levitating candle trick. I have included a link to show you how magician use this same technique only with a small sphere.
(sorry about this first link but it shows the floating effect)
(this link shows a woman using the floating sphere, it takes a while before she gets to it though)
If you need me to draw you plans for this, or even build one, I can just write me an email.
Thanks for viewing my posts!