Stree movie is based on an urban legend Nale ba, a Kannada phrase which means come tomorrow.
Full Story Of Stree
Nale Ba was an urban legend viral during the 1990s in Karnataka. The myth goes “a witchroams the streets in the night and knocks the door. The witch apparently spoke in voices of your kin so you would be deceived to open the door. If you open it then you will die.” So the residents came up with a smart idea of writing ‘Nale Ba’ (means ‘come tomorrow’ in Kannada) outside the doors and the walls of their house. So when the ghost reads it and it goes back to come again the next day and the cycle repeats.