What does it mean to put an axe under the pillow?

Mainly used for children and women to have nightmares at night. Children are constantly frightened and crying at night, which can play a role in suppressing evil spirits. Generally speaking, it doesn't have much effect after a long time. When the doctor can't find the disease, I will find some people who are said to be fantastic. This method is sometimes used. Ordinary people can't use it indiscriminately.