One of the terrifying ones is about a family that moved into a new neighborhood. Their daughter started to talk about an invisible friend. But then, things in the house began to move on their own. The family found out that a murder had occurred in the house years ago, and it seemed the spirit was not at peace. The daughter's 'friend' started to become more aggressive, and the family felt constantly in danger.
One terrifying short ghost story is 'The Beckoning Fair One'. A writer moves into an old house to work. He starts seeing a female figure that lures him into a trance - like state. It's terrifying as he slowly loses his grip on reality and is being drawn into the world of this unknown, ghostly presence.
Often, they have an element of the unknown. For example, in many short ghost stories, the origin of the ghost is not clearly defined. This lack of knowledge creates fear. Another characteristic is the use of atmosphere. A dark, quiet setting like an old house or a deserted forest can make the story scarier. For instance, in stories set in old mansions, the creaking floors and dimly lit hallways add to the terror.
One common theme is the unknown. Stories often play on our fear of what we can't understand or explain, like in 'The Monkey's Paw' where the power of the paw is mysterious. Another theme is death. Many of these stories deal with sudden or unexpected death, as in 'The Lottery'. Also, madness is a theme, such as in 'The Yellow Wallpaper' where the narrator slowly loses her mind.
One of the most terrifying is 'The Tell - Tale Heart' by Edgar Allan Poe. It's about a man who kills an old man because he can't stand the old man's 'vulture - like' eye. The guilt drives him insane as he imagines he still hears the old man's heart beating even after the murder.
In my opinion, 'The Call of Cthulhu' is one of the most terrifying. It involves an ancient, otherworldly being that drives people mad just by the knowledge of its existence. It's a Lovecraftian horror that plays on the fear of the unknown and the cosmos.
The story of the Donner Party is also extremely terrifying. A group of settlers got stranded in the mountains during winter. Due to lack of food, they resorted to cannibalism to survive. It shows the extreme desperation and horror that humans can face in dire situations.
Isolation also plays a major role. Take 'The Lighthouse' for instance. The two lighthouse keepers are isolated on a small island, and as strange things start to happen, they have no one to turn to. The sense of being alone in the face of the unknown is very frightening.
The unknown is a very terrifying element. For example, in stories where there are strange noises in the dark woods. You don't know what's making those noises, whether it's a wild animal or something more sinister. Another terrifying element is the isolation. When the characters are alone in the middle of the forest, far from any help, it makes the situation scarier. Just like in the story where the hiker was lost and had no one to turn to.
The unknown. Like in the stories where you hear noises but don't know what's making them. It could be an animal, but it could also be something supernatural. This sense of not knowing what's out there in the dark forest or by the lakeside is really terrifying.