A high-ranking Midwest officer of the Service Employees International Union, who had been serving as trustee of a financially troubled local, has resigned after being accused of billing the labor organization for $9,000 in personal expenses. The Chicago-based Byron Hobbs, who also sat on the union's national board, is the latest of several SEIU officials to lose their positions or otherwise come under scrutiny for alleged financial improprieties. Among them is Tyrone Freeman, former president of the union's largest California local, who is the target of a federal criminal investigation. Hobbs could not be reached for comment. He was executive...