Call a priest! Or the cops. Or, a therapist.

We see one of the few times the dead actually come back and interact with characters in Shakespeare's play. The only other ones I can think of off hand is Hamlet and Richard III. In any of the plays, he has a reason for calling people from beyond. In Hamlet, King Hamlet seeks out his son to avenge him. If he was scared at all, Hamlet did a good job of hiding it. Of course, he had nothing to hide, either. It wasn't his fault his dad was killed. Richard, of course, hacked and slashed his way to the crown, then killed some more to stay in power. I can't remember from class, but it looks like Richard is visited by the ghost while he's sleeping. In this case, seeing ghosts may reflect that even killers have there psychological limits, as he seems to lose a sense of reality upon waking.

Then we have Macbeth. He has been seeing things for awhile, starting with the phantom dagger in Act 2 scene 1 and then the ghost of Banquo in Act 3 scene 4. Despite his claim that "[Banquo] canst not say I did it" (3.4.49), he obviously feels either guilty or paranoid about the deaths in the first place.

This goes back to Lady Macbeth's comment of her husband being too kind in Act 1 scene 5. How kind is he, and on whose standards? On the one hand, it's Lady Macbeth that's saying this, meaning Macbeth may simply be anything but evil. On the other, maybe she's right. It doesn't seem like he would have attempted to be king had the witches stayed silent. That being said, he must have been as loyal as he claimed he was in 1.4.23-24. Unless I missed something, I don't think anyone's onto him, so his slate may have been clean up until this play.

I don't know if Macbeth loses the throne due to his own mis-step or if someone fairly takes it from him since I haven't read it before, but I'd be surprised if he lasted that long in terms of his mental status. The way he reacts each time he sees some other worldly apperision leads me to think that he's going to make a mistake. The only reason I doubt that he'll pull a Tell Tale Heart and confess is the amount of ambition he does have. After all, you have to have a strong desire to be king to not back out after killing one man.