Terminator 3 actor Nick Stahl, who had been missing for more than a week, has checked himself into rehab, his estranged wife told media outlets on Sunday. Stahl\'s wife Rose Murphy told E! Online celebrity news website that the actor, who has a history of substance abuse problems, was \"really working hard\" at sobriety. The 32-year-old American actor had been reported missing to police earlier this month. He sent an email to friends and family on Friday saying he wanted to check into rehab for 30 days.Stahl had been spotted in the skid row area of Los Angeles last week, and his wife had said she believed drugs may have played a part in his disappearance. A Los Angeles police spokesman was not immediately available to comment on whether the missing person case had been closed. Best known for his roles in Sin City and as John Conner in Terminator 3: Rise of the Machines, Stahl has been married to Murphy since 2009, but the pair recently separated. The couple has one daughter.