To look for who is telling a story, you are looking to determine the story's point of view. Point of view can be first ( when the speaker uses I or me), second ( the rarest point of view that uses you), and third (when the narrator uses he, she or they) to tell the story. Third person narration allows for an outside voice to tell what is going on with the characters because the narrator is not actually a character in the text, but an outsider explaining the events that unfold.
In Shirley Jackson's "The Lottery," we see third person narration at work. Since our narrator is not a member of the town (and their barbaric actions) the third person narration allows the reader to have an objective voice delivering the story without bias or emotion.
Soon the men began to gather. surveying their own children, speaking of planting and rain, tractors and taxes. They stood together, away from the pile of stones in the corner, and their jokes were quiet and they smiled rather than laughed. The women, wearing faded house dresses and sweaters, came shortly after their menfolk. They greeted one another and exchanged bits of gossip as they went to join their husbands. Soon the women, standing by their husbands, began to call to their children, and the children came reluctantly, having to be called four or five times. Bobby Martin ducked under his mother's grasping hand and ran, laughing, back to the pile of stones. His father spoke up sharply, and Bobby came quickly and took his place between his father and his oldest brother.
This passage shows our third person narrator explaining the men getting ready for the lottery. With detail, the narrator explains the members of the town as the begin to gather: what they are wearing and how they are interacting. You can see here that the narrator does not refer to him or herself, just the members of the town- a trait of the third person narration.