Why did Sai Baba eventually break the sleeping plank that was suspended from the ceiling?

The reason Maharaj broke the plank is directly related to the attention it attracted. According to the Introduction (Chapter 0), his unique sleeping arrangement caused many people to gather simply to witness the spectacle. They would stand at a distance to watch, curious about how he got onto and off the plank, which no one ever saw. Because so many people started gathering for this purpose, Maharaj considered it a distraction. Therefore, as Chapter 0 explains, he one day broke the plank specifically to remove this distraction and stop the crowds from forming.