The officers responded to calls and found the 35-year-old man "attempting self harm" in Wangee Road, Lakemba, just before 9am, police said.

He was taken to Canterbury Hospital in a critical condition, NSW Ambulance Service said.

A police critical incident team is heading to the house. The homicide squad has also been told about the shooting.

No police officers or paramedics were hurt, police said.

It is not clear whether the officers involved were carrying stun guns.

Last year Police Commissioner Andrew Scipione said the use of stun guns could have prevented the shooting death of Roni Levi on Bondi Beach in 1997.

On June 28, 1997, the French photographer waded fully clothed into the Bondi surf carrying a large kitchen knife. When he returned to the sand, he was surrounded by officers who, with guns drawn, ordered him to drop the weapon.

After a tense encounter witnessed by a packed promenade, Mr Dilorenzo and fellow constable Rodney Podesta fired two bullets each.

Support is available for anyone who may be distressed by calling SANE Helpline 1800 18 7263; Lifeline 131 114; or beyondblue 1300 22 46 36.