One that stands out is 'I heard a child laughing in the empty school at night.' Empty schools at night are already spooky places, and the sound of a child's laughter when there should be no children there adds to the horror. It makes you think about the possible reasons for the laughter. Is it a ghost of a child who met an untimely end? Or is it something even more sinister?
A memorable one is 'I can't sleep at night because I keep hearing my name being whispered in my ear, but there's no one there.' It gives that feeling of being haunted and makes you shiver at the thought of an unseen presence that knows your name.
One could be 'The last person on Earth sat alone in a room. There was a knock on the door.' It's terrifying as it makes you wonder what could be knocking when there's supposed to be no one else left.
Relatability also plays a part. If it's something that could potentially happen in real life, it's scarier. For instance, 'I heard my name whispered in an empty house I just moved into.' Most people have been in an empty house before, and the thought of hearing something like that is terrifying.
Another one might be 'The old doll in the attic blinked. I'm sure it did.' This simple line creates a sense of unease as dolls are often associated with the uncanny. The idea of an inanimate object like a doll showing signs of life is quite terrifying.
A good one often plays on common fears. For example, the fear of the unknown. Like 'The doorknob turned slowly in the middle of the night.' It doesn't tell you who or what is turning it, leaving your imagination to fill in the terrifying blanks.