Surprise is a key element. For example, if in a spooky old house, a character thinks they are being haunted by a ghost, but it turns out to be their cat knocking things over in a clumsy way. The unexpected nature makes it both scary at first and then funny.
Misdirection can also do the trick. In a story, if the narrator leads you to believe there is a dangerous monster lurking in the forest, but then reveals it's just a friendly, albeit very large, deer with big antlers that scared the characters by accident. This creates that funny but scary feel. The characters' over - the - top reactions to what they think is a threat can also add to the humor and scariness.
The use of contrast between the normal and the abnormal is important. Say, in a seemingly ordinary town, people start to notice that all the clocks stop at the same time every night. This is scary as it's an unexplained and strange phenomenon. But then it's discovered that it's just a naughty kid with a magnet going around to all the clocks. The normalcy of a kid's prank against the backdrop of the spooky event makes it funny and scary.
One element is misdirection. For example, when you think it's a real ghost but it's actually something mundane like a cat knocking things over in a spooky - looking old house. Another is the reaction of the characters. If they overreact to a non - ghostly situation, it can be both scary at first and funny later. For instance, when someone screams at a floating balloon thinking it's a spirit in a haunted place.
Surprise is a big element. For example, if a character is expecting a ghost but it turns out to be a prankster friend in a white sheet. Another element is the use of over - the - top reactions. If a person screams like crazy at a little mouse thinking it's a monster, that's both scary (for the person in the story) and funny for the reader. Also, the setting can contribute. A spooky old castle that has a bunch of goofy - looking bats flying around can be both scary and funny.
Surprise is a key element. For example, when you expect a terrifying monster but it turns out to be something harmless like a cat wearing a spooky mask. It gives that initial scare but then the realization is funny.
The character of the ghost can make a story both scary and funny. If a ghost is supposed to be this menacing entity but has a clumsy side. For instance, a ghost that tries to float menacingly through a wall but gets stuck halfway. The setting also plays a part. An old, dark cemetery is a spooky setting, but if the ghost there is more interested in playing pranks like making the tombstones light up in funny colors instead of scaring people in a traditional way, it creates that scary - funny mix. And the reactions of the human characters are important too. If they overreact to a not - so - scary - looking ghost or underreact to a really spooky one, it adds to the humor while still maintaining the scariness.
A big part is when the ghost is more like a friendly neighbor. Maybe it's a ghost that leaves little gifts for the living, like a ghost who leaves beautiful feathers or shiny stones on people's doorsteps. And if the reactions of the people in the story are comical, like over - reacting to the tiniest sign of the ghost but then realizing it's harmless. Also, when the ghost has a cute appearance rather than a menacing one, like a small, pudgy ghost that waddles around instead of gliding menacingly.
One element is when the ghost has comical habits. For example, if a ghost is always losing its head and then running around looking for it in a panicked yet funny way. Another is when the ghost is more interested in silly human things like fashion or dancing. A ghost that tries to learn the latest dance moves but keeps floating off in the wrong direction can be really funny.
Mismatched situations play a big part. Picture a big, tough - looking guy being terrified of a tiny spider. It's scary for him but hilarious for others. Also, the use of spooky settings like a dark forest or an old attic, and then having something really silly happen there, like a group of kids finding a lost puppy instead of a monster, makes for a great scary - funny story.
Exaggeration also plays a role. If a character is overly paranoid about every little sound in an old mansion thinking it's a ghost, and then the 'ghost' turns out to be a mouse that makes really loud noises. The extreme overreaction of the character to a normal situation is both scary in the moment and funny when the truth is known.
Surprise is key. For example, you can have a seemingly cute animal turn out to be something more menacing in a funny way, like a bunny that starts talking in a deep, spooky voice. Another element is the setting. A dark, isolated forest or an old, creaky campsite can add both scariness and a touch of humor when things go wrong there.
Surprise is a key element. For example, if a ghost is supposed to be really scary but then it trips over a broomstick, that's unexpected and funny. It plays with the audience's expectations of horror and then throws in a humorous twist.