What people really find disturbing are normal looking objects doing things they should not. Antique dolls are so old you know for a fact the original owner is dead. And gone.
One thing they don't do is float in mid air, as if supported by some invisible force.
Unless of course you use a magnetic levitation platform from eBay. You need to hide this, and I looked for a suitably creepy book to hollow out. Most cheap books are things like dictionaries and atlases. Big but not 'occult' enough. I wanted a book that was old and dangerous. Antique bookshops have old books but they are usually expensive.
Harry Potter hardbacks weren't up to the job either.
Fortunately I found an affordable copy of The Necronomicon. Not the original bound in human skin, but a collection of tales by H. P. Lovecraft. Looks new, but I'll live with that.
Most instructions about hollowing books use PVA glue. This is water-based, so paper will absorb and buckle unless you keep it tightly compressed while it is drying out - which is going to take a long time.
Being impatient, I used cyanoacrylate glue. It is very fast but using such a lot of it produces a very acrid smell. Best done outdoors while holding your breath!
Having hollowed almost every page, I realised I needed to put padding in to hold the platform near the front of the book. I could have simply just hollowed enough pages to hold the platform.
The system worked, though the positioning feedback LEDs were hidden. One has to position by feel alone.
I left it running for a while, then it stopped working. The platform uses considerable power - the PSU is 12V @1.5A, i.e. up to 18W. It can overheat in a warm room, so it is certain to do so in the closed space of a hollow book. Although thermal shutdown should fail safe, it is best not to leave it running in a flammable paper book. Do not leave running unattended. It takes just a few minutes to get hot enough to shut down.
More recent platforms shut down power slowly, so the disc gradually comes to rest. Mine turns off abruptly, and the disc slams into the base.
I have not thought of a way to keep it cool covertly. Heatsinks and fans are visible and audible. Perhaps the book could sit on a base with hidden liquid coolant?
I have not found a doll head that is both light enough to be supported and large enough to hide the floating magnetic disk. The large head on the left of the photo was too heavy but used in another project. The small head and tiny baby did not cover the disc. Maybe a pentangle painted on the disc would make it more occult and less high-tech.
I hope I've fired your imagination for similar Halloween projects...