Halloween Jokes

Q: What do ghosts eat for supper?
Ghost: THE SOULS OF SCREAMING CHILDREN
A: Spooketti!
Ghost: What
Q: Why are ghosts so bad at lying?
Ghost: Death frees us from mistruths and deception
A: Because you can see right through them!
Ghost: What purpose does spreading this misinformation serve

This was found by my wife on the facebooks. I have no knowledge where it originally came from, but it probably was from some awesome person, so props to them.

This is funny for multiple reasons: for one thing it contains multiple jokes. I will analyse each joke separately, and then attempt to analyse them all together.

Q: What do ghosts eat for supper?

A: Spooketti!

This is a joke based on a portmanteau. The two words that the portmanteau is formed from are spooky and spaghetti. The reason why this is funny is because it is an attempt at invoking the idea of food and spookiness at the same time.

Q: Why are ghosts so bad at lying?
A: Because you can see right through them!

This is a joke based on a pun that combines both a colloquial phrase and a bit of ghost mythology. In some mythologies, ghosts are either transparent, translucent, or both. This combined with the phrase "You can see right through him", which is used to mean that you can tell easily if they are lying. In this joke, they are using both meanings of the sentence.

Now, the harder jokes follow:

Q: What do ghosts eat for supper?

Ghost: THE SOULS OF SCREAMING CHILDREN
A: Spooketti!

This is funny because of the juxtaposition of the two answers. On the one hand we have something that could have come out of a straight faced horror novel, and the other answer is silly and childish. Having both answers immediately following each other makes for such a contrast that the dissonance is humorous.

Finally, 

Ghost: What
Q: Why are ghosts so bad at lying?
Ghost: Death frees us from mistruths and deception
A: Because you can see right through them!
Ghost: What purpose does spreading this misinformation serve

The final joke is probably the best one (in my opinion). This joke is based on the apparent fact that ghosts are different than normal humans. They are both apparently unable to lie, and also unable to understand humor. They seem to be bound entirely by the laws of logic and therefore unable to understand jokes. This is funny because when people do not understand things that you do, it is funny. The hearer can feel superior to the ghost, and therefore laugh at its expense. Basically this is a racist joke against ghosts.