Emergency services were called to Essential Energy on Buller Street at 5pm on Thursday, November 24 after reports there was a suspicious package on site.
Mid North Coast Inspector Mick Aldridge said police consulted the bomb squad and they reviewed CCTV footage which revealed that the object was not dangerous.
The object was a sports bag which contained clothes and football boots. It had been left behind in the building accidentally.
Police, paramedics and Fire & Rescue NSW attended the scene.
At 6pm the area was declared safe by police who investigated the building.