The authors message in the monkeys paw by W.W.Jaccobs, is to be careful what you wish for. In this story the main character Mr.White uses the paw and wishes for 200 pounds and receives it as compensation for his sons death. "His father, smiling shamefacedly at his own credulity" (Jacobs 140). So this proves that The authors message is to be careful what you wish for.
The author creates the message by the use of descrptive words or phrases like "It twisted my hand like a snake" (Jacobs 159-160). Another way was with symbolism, in the story the paw represents an evil object. The characters fit the story because they use a weak old man who isn't rich but isn't poor. He also loses his only son. The plot also helps the story because his son died first but then he wishes him back to life then wishes again in which you would assume he wished him dead.