The element of spookiness without being too scary is key. It can have things like a creaking door or a cold breeze when the ghost appears. This gives the 3rd graders a bit of a thrill. Also, a happy ending is important. Maybe the ghost finds peace or the kids learn something valuable from their encounter with the ghost. This makes the story not only interesting but also a positive experience for young readers.
Simple language. Using words that 3rd graders know makes it accessible and easy to understand. For example, short sentences like 'The ghost was white.' rather than complex descriptions. Also, relatable characters like kids their age. If a 3rd grader can see themselves in the story, like a kid exploring a spooky place, it's more engaging.
A good 3rd grade ghost story has a clear plot. It doesn't have too many twists and turns that would confuse young readers. For instance, a story where a ghost is looking for something and the kid helps. And there should be some element of mystery, but not too much. Just enough to keep them curious, like a strange noise in an old house that turns out to be a friendly ghost.