It happened in the 100 block of Gregory Drive. Firefighters arrived and found smoke coming from one side of a duplex.
The fire was quickly contained and extinguished.
One person was taken to a hospital for treatment of minor injuries and smoke inhalation.
No other structures or homes were affected by the fire, a Cary town official said, and no one was displaced.
The cause of the fire is still under investigation, but a spokesperson said an unattended candle may have been to blame.
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