Mo Dou is a carpenter's tool. It looks a bit like a boat, more than 20 centimeters long. Carpenters sometimes draw a straight line on the wood so that they can hold it straight when they take it. But it's too much trouble to draw with a ruler, so I use Mo Dou. There is a head behind Mo Dou, and it is a black line dragged out. Usually this black line is soaked in the Mo Dou, and there is ink in the Mo Dou, so one person fixes his head at one end of the wood, and the other person straightens the line, and then straightens it and fixes it. At this time, pull up the thread, loosen it, play it casually, leave a straight ink mark on the wood, and you can straighten the wood. As for exorcism, I didn't know that my grandfather was a carpenter when he was young. He used to play when he was young, but now he seldom plays.