One example could be 'I woke up in the middle of the night. There was a figure at the foot of my bed. When I blinked, it disappeared.' Another is 'Walking in the old attic, I heard a child's giggle. I was alone.'
A '10 second horror story' could be this: I was home alone. The lights started flickering. I heard a low growl from the basement. Also, there's this story. I was looking in the mirror and for a split second, my reflection had a sinister smile that wasn't mine.
One example could be 'In the old attic, I found a doll. Its eyes followed me. Then it smiled.' Another might be 'Walking alone at night, a hand grabbed my ankle from the sewer grate.'
One example could be 'I opened the old, creaking door. A cold hand grabbed my wrist. Then it was gone.' Another might be 'Walking in the dark forest, I heard a growl. I turned. Red eyes stared for a split second, then vanished.'
One possible ending could be a sudden loud noise that startles the reader. For example, 'The door creaked open slowly, and just as I peered into the darkness, a deafening screech filled the air.'
One example could be 'I opened my eyes in the dark. A hand touched my face. Then I woke up for real.' Another might be 'The elevator doors opened. No one was there but I heard a child's laugh. Door closed.'
In some hide two second horror stories, the ending could be a realization that the threat was much closer than expected. After the two seconds of hiding, the protagonist discovers that the source of horror, like a menacing entity, was right inside the hiding place with them all along. They only notice when it's too late as it reveals itself in a terrifying way.
One example could be a story where a person takes a psychedelic drug and then starts seeing grotesque and menacing creatures that seem to be chasing them through a distorted version of their own home. They can't escape these hallucinations and feel a sense of extreme terror as the creatures get closer and closer.
She heard a strange noise from the attic. When she opened it, a pair of red eyes stared back.
One example is 'The Phantom of the Opera'. The music in it adds a lot of mystery and horror. The phantom's powerful and sometimes eerie singing, along with the grand yet spooky musical scores, creates a truly horror - like atmosphere. Another could be 'Sweeney Todd'. The dark and menacing tunes accompany the story of a vengeful barber, making the whole plot even more terrifying.
One example could be a story where a furry character gets trapped in an abandoned, haunted laboratory. Strange experiments were once carried out there, and now the furry is being haunted by the ghosts of the failed test subjects. Another could be about a furry village that is invaded by a dark, shadowy creature that feeds on the life force of the furries, slowly draining them of their energy and leaving a trail of lifeless, desiccated furry bodies.
One example could be a kitchenette where the stove constantly has a gas leak smell. It makes you fear for your safety every time you want to cook. Another could be a really tiny kitchenette with no proper ventilation, so it gets extremely stuffy and smelly when you cook anything.