One interesting element is the contrast between the spooky nature of ghosts and the humorous situations they get into. For example, a ghost being afraid of a little mouse. Another is the way ghosts interact with the living in a comical way, like a ghost trying to use modern technology but failing miserably.
Well, the use of the unexpected is a big part. A ghost that loves to dance disco instead of scaring people. Also, the way the ghost's 'ghostly' abilities are used for comical ends. For instance, a ghost who can float but keeps getting stuck in trees or chimney pots because he's not very good at controlling his floating. And their unique personalities, like a very shy ghost who blushes (even though he's transparent) when he's around people.
One common element is the ghost having a unique quirk. For example, a ghost that is obsessed with modern technology like smartphones and tries to use them but keeps failing in a comical way. Another element can be the interaction between the ghost and the living. If the living characters are not too afraid and instead play along with the ghost's antics, it creates humor. For instance, when a family invites the ghost to their dinner table and the ghost tries to eat but the food just passes through him, causing everyone to laugh.
Another might be about a pet causing chaos during a family gathering and the hilarious consequences. There could also be a story of a mix-up at a supermarket that leads to unexpected and funny situations.
Sure. Here is one. A ghost was trying to scare a man in an old house. The man was eating a sandwich and just looked at the ghost and said, 'You're late for lunch. There's only half a sandwich left.' And the ghost was so surprised that it disappeared.
Sure. There was a ghost who was a terrible cook. He haunted an old kitchen, and whenever he tried to make 'ghostly' treats, like ectoplasm pancakes, they always turned out lumpy and gooey. His spooky friends would come over and pretend to enjoy them, but really they were just being polite.
A group of ghosts were having a competition to see who could be the scariest. One ghost decided to appear as a headless horseman. But when he rode out, his horse tripped over a stone and he flew off, yelling 'Ouch! This is not how it was supposed to be!' All the other ghosts couldn't help but laugh.
One element is the unexpected behavior of the ghost. For example, a ghost that is afraid of the dark instead of scaring people in the dark. Another is when the ghost interacts with the living in a comical way, like a ghost trying to use modern technology and failing miserably. Also, the setting can be interesting. If the ghost haunts a place like a toy store and has to deal with all the moving toys, it can create a really funny situation.
There could be a story about a possessed object. In the book, it might tell of an old doll that has a malevolent spirit. The doll moves on its own, and its eyes seem to follow people around the room. Whoever comes into contact with it starts to experience strange and terrifying events, as if the spirit within the doll is trying to cause harm.
A ghost floated into a bar. The bartender looked at it and said, 'Sorry, we don't serve spirits here.' The ghost was so confused and left. Another one is that a ghost was trying to make a spooky face at a dog. But the dog just licked the ghost's face and the ghost ran away screaming in a funny way.
There might be a story of a park that was built on an old cemetery. People often see shadowy figures among the trees at dusk. These figures seem to be wandering aimlessly as if they are still attached to the place where they were buried.
There was a child who felt a presence in his room every night. When he asked who it was, a faint voice said 'I'm lost'.