Joseph´s Shadow

There was a boy who liked to read spooky tales at night. One day his mother called him to go to bed. His name was Joseph. His mother closed the door his room and he looked for a spooky tale to read. He started to read and a shadow started to appear on the wall, the shadow was like a ghost.
"I will not read more spooky tales. I promise" Joseph said and the shadow went away.
Next morning, having breakfast, Joseph told his mother what had happened, but she didn´t believe him. Joseph went out very sad. If his mother didn´t believe him, he was hoping his friends would do it. But it didn´t work, they called him "Crazy Shadow Boy".
At night, he started to read books again and the same shadow appeared. Next morning, he was thinking about something to take the shadow away. At night he waited for the shadow, when it came Joseph said:
"I don´t want you. You have to go!". The shadow started to laugh very loudly.
Next night, while Joseph was reading a book, waiting for the shadow, it appeared and asked him:
"What are you going to do tonight?"
Joseph looked at it and turned off the light; then, he said:
"Without light there´s no shadow"