Mary Downing Hahn

When twelve-year-old Florence boards the crowded horse-drawn coach in London, she looks forward to a new life with her great uncle and aunt at Crutchfield Hall, an old manor house in the English countryside. Anything will be better, she thinks, than the grim London orphanage where she has lived since her parents' death.
But Florence doesn't expect the ghost of her cousin Sophia, who haunts the cavernous rooms and dimly lit hallways of Crutchfield

...

While spending the summer at their grandmother's Vermont inn, two prankster siblings awaken young ghosts from the inn's distant past who refuse to "rest in peace."

Having just moved into the West Virginia home they inherited from a distant relative, twelve-year-old Jen is surprised that her father is already dating a local antiques dealer, but more surprised by what the spooky woman really wants.

When thirteen-year-old Ali spends the summer with her aunt and cousin at the family's vacation home, she stumbles upon a secret that her mother and aunt have been hiding for over thirty years.

"A witch called Old Auntie is lurking near Dan's family's new home. He doesn't believe in her at first, but is forced to accept that she is real and take action when his little sister, Erica, is 'took' to become Auntie's slave for the next fifty years"--

Unnerved by the overgrown forest near her aunt's house and the wild black cats that live there, Danni encounters a mean old woman who claims to be their owner and makes a discovery that places her life in danger.

"Eleven-year-old Brendan Doyle doesn't get along with his foster mother, he's failing fifth grade, and he's bullied mercilessly by a band of boys in his class. Then Brendan meets two potential friends--an eccentric old man and a girl from summer school--and he sees that there may be hope for him after all"--

When he goes to spend the summer with his great-aunt in the family's old house, eleven-year-old Drew is drawn eighty years into the past to trade places with his great-great-uncle who is dying of diptheria.

When Matt and Parker learn the body they found in Indian Creek is a drug-related death, they fear Parker's mother may be involved.

"Travis and his sister, Corey, can't resist a good trick. When they learn that their grandmother's quiet Vermont inn, where they're spending the summer, has a history of ghost sightings, they decide to do a little "haunting" of their own. Before long, their supernatural pranks have tourists flocking to Fox Hill Inn,and business booms. But Travis and Corey soon find out that theirs aren't the only ghosts at Fox Hill. Their thoughtless games have awakened...