For consultation, I live in a house on the fifth floor and the second floor. I knock on the wall with a hammer every night from 9 pm to 6-7 am.

First, call the police. But the reality is that the police are very busy, and the police are unwilling to take care of such general illegal acts.

Secondly, this situation is best solved through the neighborhood Committee of the community where you live. There are generally mediation committees under the neighborhood Committee. Let the neighborhood Committee contact his guardian.

Finally, if it is really impossible, because his behavior has violated your neighboring rights, you can sue in the people's court to stop the infringement. If the other party is a mental patient, his guardian shall bear the liability without fault.