I am reading Hamlet and was curious if there is "evil" revealed in the characters of the play.
I am trying to find the evil in the characters such as Hamlet killing the wrong guy or something similar.
In Shakespeare's play, Hamlet, corruption abounds throughout the court. There is, indeed, "something rotten in Denmark"as Marcellus remarks. For, the long-winded Polonius is a hypocrite who gives his son advice while he has someone spy on Laertes and while he himself acts as a spy for the queen. Hamlet's erstwhile friends, Rosencratz and Guildenstern, betray him by spying for Claudius. Gertrude betrays her dead husband and her son by marrying Claudius. Laertes, who returns for the coronation of Claudius, accuses Claudius of the death of his father, Polonius, but is talked into a plot to kill Hamlet, after Claudius convinces him that it is Hamlet who is responsible for the death of Polonius.
After Hamlet talks with his foil, Fortinbras, he realizes how corrupt his court is in contrast to the noble young man. So, Hamlet, Prince of Denmark, decides to take action against this corrupt court. As he dies, with the other courtiers already dead or dying, Hamlet asks Fortinbras to reclaim for his own father the land that was theirs. He gives the crown to Fortinbras.
Look to the other members of Hamlet's court for evil; there it abounds in hypocrisy and in treachery.
Concerning Shakespeare's Hamlet, you're looking at the wrong character if you're looking at Hamlet for the presence of evil.
Hamlet's killing of Polonius is a mistake. He thinks it's the king behind the arras when he kills Polonius:
I took thee for thy better. (Act 3.4.32)
Hamlet can be accused of cruelty in his treatment of Ophelia and Resencrantz and Guildenstern, but not evil. His treatment of those he hurts is the natural result of the wrongs they do him, as least in part. If he errs, it is in his going too far.
If you want evil, examine Claudius. He kills his brother, a sin on a level with Cain killing Abel, then marries his brother's wife, which is seen as incest in his society. Once he knows Hamlet knows about his murder of King Hamlet, he arranges for Hamlet's execution in England. When that fails, he plots to underhandedly kill Hamlet by unblunted sword and poison.
Finally, Claudius knows his actions are evil and he knows he is eternally damned, but he still refuses to give up his ill begotten gains, so to speak. He would like to be forgiven, but he is unwilling to give up what his sins helped him achieve. As he says while praying:
O, what form of prayer
Can serve my turn? 'Forgive me my foul murder'?
That cannot be, since I am still possessed
Of those effects for which I did the murder--
My crown, mine own ambition, and my queen.
May one be pardoned and retain th' offence? (Act 3.3.51-56)
If you're looking for evil, Claudius is your man.