There is an abandoned house in your fictional neighborhood. It has been abandoned for decades under mysterious circumstances. No one knows where the owners went. But for some reason the house was never sold again and the city has never torn it down.
The rest of your fictional neighborhood is up to you, the one essential part of this writing prompt is the abandoned house. Before your prompt is finished your main character has to enter this house.
You get to decide who that character is, you get to decide why they are entering the house, you get to decide what happens when they are inside the house.
There are only two essential components to this prompt. The first is that there is abandoned house near your main character’s house, the second is that your main character must enter that house. Everything else is up to you. Have fun writing this. Explore your options.
This is one prompt I have done multiple times with interesting and very different results