Build upon the Poltergeist movie.

Back in 1982 the newly build Canterlot alley was often visited by tourists, and crowds came by to visit the shops and more. Lots of ponies came to the cafes, bookstores and on. But ponies avoided a haunted house in that alley. A family of ponies from Manehattan moved to that house. The Summer Sun Celebration came, and the family went to the crowded fair with rides, food, stalls and more. Later after Princess Celestia had raised the sun that morning, were the pony family going to bed. But soon were the filly waking up. The filly saw and heard ghostly ponies. None of the ghostly ponies looked scary. As the filly tried to talk to the angel like ponies, did she not understand their language. Strange noises and strange music filled the house.

"You are so beautiful." the filly told the angel like thing and smiled.

It was not an alicorn or pegasus just something else.

"What the hay is that." the father said to the mother.

"She is talking to something invisible." the mother told the father.

1988 came, as the six ponies and Spike had dinner in Ponyville the day before Nightmare Night. Rainbow Dash told the ponies about that haunted house who had vanished.

"That little filly will gobble you up." Rainbow Dash told her friends.

"She is evil." Pinkie Pie said to Rainbow Dash.

"You are scaring both Applejack and Fluttershy, and this is just some filly stories." Twilight told her two friends.

Filly story or none of that Twilight went to a bookstore in Canterlot that day.

"It is true my filly that a haunted house once stood beside here." the Saddle Arabian stallion told the unicorn pony.

So Twilight found a book about that place. Luna tried to do an exorcism on the house, but it failed. The hauntings stopped as the family moved away from Canterlot, and they found remains of bison tribes under Canterlot.

"Since that day Nightmare Night had been held every autumn for Luna." Twilight read in the book.