Why are ghosts such bad liars?

Because you can see right through them.

Did You Know?

"See right through them" works two ways — ghosts are transparent (literally see-through), and bad liars are easy to detect (figuratively see-through)! The concept of ghosts being transparent comes from spiritualist photography in the 1860s, where double exposures created translucent "spirit" images. Interestingly, different cultures depict ghosts differently — Japanese ghosts traditionally have no legs, while European ghosts wear flowing white sheets!