Symbolism, Imagery, Allegory
You know what's kind of crazy (okay, one of the many things that are kind of crazy) about the way Scrooge gets his groove back? It's very, very invasive. Now, Shmoop isn't a psychiatrist and doesn't even play one on TV, but there's something about the fact that everyone who tries to reform Scrooge-the-loner keeps on breaking into his bedroom that smacks to us of the traditional treatment for phobia.
What's that you ask? It's constant exposure to the thing you're scared of.
And the object that seems to register highest on Scrooge's invasiveness scale is none other than his bed—arguably the most private and isolated place in his house, or anyone's house for that matter. Think about how many times Scrooge is pulled into and out of his bed. The Ghost of Christmas Past opens up his bed curtains to reveal a terrified Scrooge. The Ghost of Christmas Yet to Come turns into one of the bedposts when it melts away, and each time a ghostly adventure is over, Scrooge finds himself plopped back into his four-poster.
But the real kicker comes from the possible future that Scrooge sees while traipsing about with the Ghost of Christmas Yet to Come. You know, those three thieves who have made off with his stuff after his death? The most appalling of these is the charwoman, who makes off with… well, let's let her tell it:
"Bed-curtains!"
"You don't mean to say you took 'em down, rings and all, with him lying there?" said Joe.
"Yes I do," replied the woman. "Why not?"
[…]
[Scrooge] recoiled in terror, for the scene had changed, and now he almost touched a bed: a bare, uncurtained bed: on which, beneath a ragged sheet, there lay a something covered up, which, though it was dumb, announced itself in awful language. (4.64-78)
Even the pawnshop guy, who apparently is used to this kind of thievery, is floored by the idea that this corpse was so unattended that the woman could have actually removed the curtains from the bed without anyone giving a hoot.
Also, check out how the fact that the bed is "uncurtained" and "bare" makes the scene with Scrooge's corpse look even more chilling and horrifying. In the novella, this violation of the bed is pretty much the ultimate invasion—since Dickens isn't willing to have Scrooge's actual body be harmed in some way.
And finally, what's the first thing Scrooge turns to in his immense relief that he gets to Mulligan his life? You guessed it—the bed:
Yes! and the bedpost was his own. The bed was his own, the room was his own. Best and happiest of all, the Time before him was his own, to make amends in! (5.1)