The man, who was wearing khaki pants and a blue polo instead of a TSA uniform, was allegedly able to grope two women he brought into a private booth for pat-downs.
His outfit was similar to those of a private security firm that conducts screenings at the airport. He may have donned a pair of plastic blue security gloves to help him look like an agent, CBS San Francisco reported.
Actual security staff members figured out something was amiss because male agents are not supposed to pat down female passengers without a female agent present.
The 53-year-old was a ticketed passenger.
The man was arrested on suspicion of public drunkenness, Sgt. Wesley Matsuura of the San Mateo County Sheriff's Office told SFGate. Matsuura declined to give further details as the investigation is being handled by the TSA.
"They will be [investigating] this for a week," another law enforcement source said. "Someone has to pay for this.''