Wish you were here short story?

wish you were here is a short story that is taught in grade nine (im in grade nine :P)

ummmm it's a story about a lady named Dorothy who buys a garden gnome. the gnome disappears and starts sending post cards to her! of course gnomes don't actually talk or write for that jatter so she is completely freaked out. over the course of the story, the gnome writes to Dorothy and says he is sick. his condition worsens and in the last telegram to her, it is written :the gnome died today. Dorothy died the when she heard the telegram delivered to her. her good friend norah finally figures out that the perpentrator is Norman, the mail man. but we don't find out his motives for what he did. could he have been a lunatic?