You could do this as a magnet story. But you'd have to make multiple sets of ghosts and keep moving them on and off the board. Awkward and not practical, especially with squirming small children.
I've used"Scat the Cat", that I'd used for years. I'm not sure where I'd gotten it originally (pre-Internet!) but a few years ago when I still had an assistant, we found it on a website with a clever gimmick. You cut the cat shape out of a file folder, slid different colors of paper into the file, then pulled them out to change the cat's color.
Hmm. If I could do "Scat" that way, could I do "The Ghost's Dinner" similarly?
Though I no longer have an assistant at work I still have The Man of the House (it's a Laura Ingalls Wilderism), my spouse of many years, veteran of many a weird library project. I showed him the book, showed him "Scat" and set him to work.
"Make it BIG,"I said. "It will be easier to handle and everyone will be able to see it in a group"
He took 2 large pieces of poster board. On one he drew the scene with the ghosts at the table and cut it out with an Xacto knife. He put a large piece of clear material (file cover, I think) on the underside of the cut outs. And then he glued it to the second piece of poster board like a pocket--leaving the right hand side open.
I taped large construction paper sheets together to slide into it. Thin colored poster board would work too since it comes in a variety of colors.
And as I tell the story, I slide each sheet out and the ghosts change color.Like this: