Hero syndrome.
Firefighter arson is one of the major reasons the term "hero syndrome" was coined and brought into popular discussion.
From Wikipedia:
Hero syndrome is a psychological disorder and the need to help someone, also a term used by the media to describe the behavior of a person seeking heroism or recognition, usually by creating a harmful situation to objects or persons which they then can resolve. This can include unlawful acts, such as arson. The term has been used to describe behavior of public servants, such as firefighters, nurses, police officers, security guards and politicians.