Pyromania

Pyromania is a psychological disorder. It is an "impulse control disorder" with an obsession with fire and explosives.
Pyromaniacs often set fire to things. They get pleasure or relief from seeing things burn. Pyromaniacs are often convicted of arson. When children have pyromania, later in life they usually are diagnosed with a mental disorder. Pyromaniacs set fire to relieve stress and it gives them pleasure and relief.
Someone with this disorder deliberately and purposely sets fires on more than one occasion. Before the act of lighting the fire the person usually has tension and an emotional buildup. When around fires, a person with pyromania shows intense interest or fascination and may also get pleasure, gratification or relief.