My Best Friend is a Ghost

12-year old Riley's best friend is Shelley, a friendly ghost girl who loves to explore, play pranks, and bake cookies. But when Riley's family moves into a haunted mansion with real ghost hunters, Shelley helps save the family from the spooky trickster ghosts living there by teaching Riley ghostbuster skills. Full storyline description:Riley is a lonely kid who has trouble making new friends since her dad's job often causes them to move around a lot.
One day a quirky, rainbow-haired ghost girl named Shelley starts following Riley home from school. At first Riley is scared but Shelley proves to be friendly and fun by baking with her and making her laugh constantly. But when Riley's family buys a creepy old mansion to renovate and sell, Shelley gets worried. She warns Riley that this "perfect" house is haunted by a group of nasty trickster ghosts who play mean pranks on living people and drive them away.
Shelley worries the other ghosts will scare Riley away too. Shelley comes up with the idea to train Riley in ghost hunting skills like detecting spectral presences, using warding circles, communicating through EVP recorders, and even specialized gadgets Shelley designed herself to combat ghosts. Together Riley and her best ghost friend work covertly to outwit the scheming ghosts and ultimately convince Riley's parents to abandon their renovation attempts rather than get hurt.
Along the way Riley comes to learn that ghosts were once real people with feelings too. With Shelley's help, Riley is finally able to convince the ghosts to move on to a better place and leave her family's dream house in peace. Let me know if you would like any additional details for this paranormal middle grade idea!