The latest blaze happened just two weeks after a 14-year-old girl was issued with a warning over allegedly setting fire to a house at Wellington. This one happened right next door.

Police are now investigating the fire at the unoccupied house in Elizabeth Street and are searching for answers to find out if it was deliberately lit.

NSW Fire and Rescue was called out at 8pm on Friday after members of the public reported seeing smoke coming from the unoccupied building on the corner of Elizabeth and Dibbs streets.

"A fire had been lit in one of the rooms of one of the vacant buildings," Fire and Rescue NSW Wellington Captain Mark Moroney said.

"The fire was extinguished and the damages contained to that room of origin but significant smoke damage had occurred (throughout the house)."

"The building had been unoccupied at the time and police have been called out for further investigation into the cause of the fire."

This is the fourth house fire in Elizabeth and Dibbs streets area within the past 12 months.