She saw him put a wad of letters into the box and her husband went to investigate.
"When I went out, I pulled them out and started to flip through," Mr Burnett said.
Forty voting papers for the Denby byelection had been delivered - 39 for Mrs Burnett, and one for Mr Burnett.
"I've counted them twice, there's definitely 39 there," Mrs Burnett said. "I just couldn't believe it."
The byelection was forced after councillor Jayne Golightly resigned in September -
less than a year into her term - following the revelation she was not a New Zealand citizen.
The couple had been laughing with their neighbours on Monday night that they must live on the wrong side of the street, as their neighbours had received two voting papers each and they were yet to receive theirs.
Mrs Burnett said she would be posting just one vote.
"I'm saving them [the other papers] because every time someone comes to visit I'm going to say 'look what happened to us the other day'."
Returning officer Dale Ofsoske from Election Services, which runs the byelection for the Whangarei District Council said it was totally unacceptable.
He said Mrs Burnett's record only appeared once in their database, as it should.
He had contacted the printers to find out what had happened and they were conducting an investigation.
There were 18 reports of people getting two voting papers.
Voting forms have a specific barcode and, once scanned, a second barcode with identical features would not be recognised by the electronic system.
Voting in the byelection closes on December 7.
