What is Red Button?

This red button represents one’s desires. Farris tells Gwendy that this button is versatile and can be pushed to get anything she desires. Once when she pushes it the place that she thinks of corresponds to the place where Jim Jones convinces his followers to commit mass suicide. The second time, Gwendy destroys the Suicide Stairs, and the third time she calls for Frankie to rot in hell after he killed her boyfriend.