There is no copyright or trademark in the term "Secret Service" or in the particular way the U.S. Secret Service functions, dresses, etc. There is also no copyright or trademark in the Oval Office design. Where there could be copyright or other intellectual property is in how other producers, artists, writers, etc. have depicted the Secret Service and Oval Office, since their specific depictions may belong to them. So base your film on the original source material, not on anyone's book, film, etc.