Mr Knight said they planned to frame the notice and put it on the mantelpiece.
"I was looking for my vehicle in it [the picture] and thinking to myself have I been to Bath?
"The poor lady walking down the bus lane has got a top on very similar to my number plate but her handbag is blocking one of the letters out so it assumed it was my number plate," he said.
Mrs Knight said she thought it was a joke but when none of their friends came forward, they contacted the council.
"When we looked at the photo it was of a lady with 'knitter' on her sweatshirt and KN19 TER is my husband's number plate.
"I think it's bizarre and very funny, this poor lady has been changed over into a vehicle rather than a person overnight, " she said.
Mrs Knight said when she contacted the council, they initially told her the fine would need to be paid but when the staff member looked at the image she "burst out laughing".