Here is a quick Halloween-style joke that works all year round: Why are ghosts so bad at lying? The answer relies on a familiar idea about ghosts, rather than anything complicated.
The answer
Because you can see right through them!
The joke has two meanings. In stories and cartoons, ghosts are often shown as transparent. Meanwhile, when someone says they can see right through a lie, it means the deception is obvious. Put those two ideas together and you have a short, playful riddle.
It is the kind of question that can make someone groan and laugh at the same time. Try asking it at the dinner table without giving away the punchline.
