To be interesting,the short story needs a simple plot and a few characters to be easy to understand,at the beginning,jump into the action and at the end,wind up the story quickly. Personally speaking,i prefer short fantasy stories or creepypastas.
And what is a creepypasta? the word creepypasta comes from "creepy" and "copy-paste" and is used for the copied and pasted horror stories of internet or short horror stories created on the internet and copied in another places. Is a word created in 4chan in 2006.
An example of creepypasta could be "Ben Drowned",is about a young man that bought a cursed cartridge of "Zelda Majora's Mask" on a garage sale,when he plays the game he begins to suspect it is haunted by a ghost of a boy named Ben,who drowned.
If you want to read the creepypasta,you can do it here: http://creepypasta.wikia.com/wiki/BEN_Drowned
(You shouldn't have done that,popular phrase of Ben Drowned)Sources: https://www.merriam-webster.com/dictionary/short%20story
http://www.aaronshep.com/youngauthor/elements.html
https://www.google.com.ar/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjlqqSqpPPTAhUCkpAKHWj0CTwQjRwIBw&url=https%3A%2F%2Fwww.cuentosinfantiles.net%2Fcuentos-caperucita-roja.html&psig=AFQjCNHTAlz1C6-Xgi39qWmXJuq7y4_Hug&ust=1494985251312749
http://vignette2.wikia.nocookie.net/creepypasta-the-fighters/images/0/05/Ben_Drowned.png/revision/latest?cb=20140727175421
https://i.ytimg.com/vi/uQ1O7M0-2DQ/hqdefault.jpg