PC Andrew Bell is alleged to have uploaded two images to the Fab Swingers website in June, last year.
One image shows him wearing a police uniform and a warrant card.
The other image showed him partially naked with his torso and genitalia on display on his profile page.
The former officer is also accused of being in an intimate relationship with a victim of crime.
A statement on the West Yorkshire Police website said: "It is alleged that he conducted himself in a manner which constitutes a breach of the Standards of Professional Behaviour in relation to Discreditable Conduct, Order and Instructions and Authority, Respect and Courtesy by, on or before June 29, 2020, uploading images of himself to a website, namely Fab Swingers.
"In a further unconnected matter, the former officer has attended at the address of a member of the public in the course of his duties on May 28, 2020, following a report that they had been subject of a controlling and coercive relationship. He subsequently engaged in an intimate personal relationship with this individual.
A gross misconduct hearing will take place at the force's headquarters in Wakefield on July 19, at 10am.