In life, the Nurse Ghost was apparently a nurse at the Vannacutt Psychiatric Institute for the Criminally Insane. She was presumably killed in 1931 when the asylum's patients revolted against the staff and started a fire that killed everyone in the facility except for five orderlies. After the Nurse died in the asylum, the Baphomet Idol kept her ghost bound to the building, along with the ghosts of everyone else who died in the 1931 revolt.
When Desmond Niles and his team come to the Vannacutt asylum looking for the Baphomet Idol, the Nurse Ghost briefly stalks Kyle and Norris in the asylum basement's corridors. Later, when Samuel wanders off, the Nurse Ghost captures him, straps him down into a wheelchair and takes him to Dr. Vannacutt. Vannacutt kills Samuel by surgically removing his brain, while the Nurse Ghost records the operation on camera.
Later, when Paul, Ariel and Dr. Hammer remove the Baphomet Idol from the Heart of the House, the Nurse Ghost and several other ghosts corner Paul in the Heart of the House. But at the last second before the ghosts can kill him, Ariel sends the Idol out of the house through the sewer, freeing the Nurse Ghost and the other spirits from Baphomet's will and causing them to cross over.