Have you ever fired someone due to erratic behavior?

mmmm yes one time fired one 

First thing you should do is; sit this person down in a quiet place. Explain to her or him what you expect and that you are giving her or him one week to become a team player! After that it will be the front door. You might ask if they have any personal problems at home. That's if you care enough. Sometimes that will cause erratic behavior. Your choice, since you are the boss this is part of being the boss letting someone go.Good luck in this matter

Not that I have never

thanks for the invitation