Up until the early hours of Monday morning Kathryn Blakemore felt safe and secure living with her 20-year-old disabled son and her sister Linda Carter.

But around 5am Monday that feeling of security turned to terror when neighbours woke the family and told them to get out of their house.

A wheelie bin had been placed between the sisters' cars and set alight, spreading to the carport and dangerously close to their home.

The pre-dawn mayhem has left the sisters fearing for their safety and Kathryn's son (who she did not want to name) anxious and in fear. He has now moved to another relative's place where he feels safe, Linda said.

"We were all in bed and woke up to what I thought was the neighbour's car alarm, but I also heard a bang," Linda said.

She said the commotion woke her neighbours who saw the bin on fire between the cars. The neighbours then noticed their own bin had been moved. They also spotted someone between their cars dressed in dark pants and a light colour hoodie, who quickly fled the scene on a pushbike.

The neighbour ran to the women's home, banging on the front door and telling them to get out before the fire spread.

Kathryn and Linda said police are now involved. They asked their street not be named for fear of reprisal.

"You can't see the carport from our bedrooms which are at the other end of the house.

"Our neighbours notified us - helped us out big time. If not for them, the house would have burned down," Linda said.

Neither Linda or Kathryn's cars were insured. Linda's Mazda 3 which has travelled only 78,000 kilometres, is beyond repair and damage to Kathryn's Toyota Corolla is currently being assessed.

They now rely on friends and family for transport and to get Kathryn's son to appointments.

"We are at a loss to understand why this happened. We have no enemies.

"Now we're frightened, we can't sleep and have no transport," Linda said.