I will show a picture that I have and the task is to write a story around it. I saw this on while walking home from at night. Anyway, I walk through this abandoned-looking, creepy part on my way home, having some kind of Urbex feeling in me. The place looks abandoned yet the lights are on. 

The genre can be whatever you want. Mystery, thriller, horror, fantasy, supernatural, etc. based on the image. Give it back story, perhaps. Be creative and have fun! 

There is no required length. Just write your story with however many words you feel comfortable.