One 'two sentance horror story' could be 'I always sleep with a nightlight. Last night, I woke up to find it was still on, but I was in complete darkness.' It's terrifying because the contradiction between the nightlight being on yet in complete darkness creates a sense of the unknown and a break in the expected reality.
A third one is 'I saw a figure in the mirror. When I turned around, it was still there.' This is scary as mirrors are supposed to reflect what's behind us. When the figure defies this norm and is still there when you turn, it shatters the safety we assume from the normal functioning of objects, making us feel vulnerable to the unknown.
One '2 sentance horror story' could be 'I woke up in the middle of the night. There was someone standing at the foot of my bed.' It's terrifying because the sudden realization of an unknown presence in your most private and vulnerable space, your bedroom at night, sends shivers down your spine. You don't know who it is or what they might do.
One: 'The mirror showed my reflection, but when I blinked, it didn't.' Another: 'I heard a knock at the door. When I opened it, no one was there, but the doorknob was cold as ice.'
Silence. Silence can be scarier than any noise. In a situation where there should be some sound, like in a forest at night where there are usually animals making noises, but instead there is complete silence. It could mean that something is lurking, waiting to pounce. It makes you wonder what's out there that has silenced everything else.
A man was walking alone in the forest. The moon was full but the trees were too thick to let much light in. He heard rustling behind him. He started to run. But then he realized the rustling was all around him, closing in.
One sentence horror story: The last person on earth sat alone in a room. Then there was a knock on the door.
One story could be 'I always sleep with a nightlight. Last night, I woke up to find it off and a cold hand on my wrist.' Another might be 'The old doll in the attic blinked. Now it sits at the foot of my bed.'
One could be 'I entered the abandoned asylum. A cold hand grabbed my ankle.' Another is 'She thought she was alone. But the eyes in the mirror said otherwise.' These short horror stories create a sense of dread quickly with just two sentences.
Another one could be 'I heard a scratching at the window all night. In the morning, there were deep gouges on the glass and no sign of what made them. The simplicity of two sentences can create a very intense and spooky atmosphere.
Here's another. 'I woke up to find the world silent. When I looked out the window, all I saw were shoes.' This is scary as the silence implies something is very wrong, and the sight of just shoes is strange and makes you wonder what happened to the people.
One night, I heard scratching at my window. I peeked out and saw a faceless figure. It vanished when I blinked.