Do We Have This One? Needs More Examples

That moment where the heroes, or maybe a Red Shirt, become aware of strange noises coming from the closet/basement/outside. For a brief moment, they hesitate not knowing whether its a crazy ax murderer or just a mouse.

They may not even be aware there is a killer on the loose, but so long as the audience knows, it counts. Obviously, this applies mostly to the horror genre, as a way to add suspense.