Where did shadow people come from?

Reading "Shadow Man", I dreamed of lighting a red candle, and the shadow man came out from the candlelight: wearing a felt hat and carrying firewood, an old nursery rhyme: jokes, jokes, jokes wearing a broken felt hat.

This seemingly simple poem left me an indelible memory in the text. When I grew up, I gradually forgot shadow people and the magical red candle. Until junior high school, I met again. The power went out, I lit a red candle again, and shadow people came out again. Same as before: wearing a felt hat and carrying firewood.