Many parents strive to always keep matches and lighters out of reach of young children. This is an area which should be free of matches and lighters. Explain how matches and lighter's are tools not toys. Often, when children play with fire, nothing happens. They develop a false sense of control over it.
Fire play is very serious.
Don't assume it is just a phase and will pass by itself. Children who play with fire can be dangerous to them selfs and others. Because children usually don't understand why they are setting fires, they can't stop without help. For assistance with a child that you may consider a current or future fire setter contact your local fire department.