At about 10pm on Boxing Day, Northumbria Police received a report that the man, aged in his 20s, had been assaulted outside a property on Cedar Grove.
Emergency services attended the property and the council employee was taken to hospital with significant injuries to his hands.
It was reported that he had been boarding up a window at the property after a bottle had been thrown through the glass earlier that day.
But as he was working a man approached him and attacked him with what is believed to have been a meat cleaver.
The suspect then fled the scene. Although enquiries are still ongoing, officers believe the incident was a case of mistaken identity.
An investigation to identify the suspect was launched and a 27-year-old man was later arrested on suspicion of attempted murder.
A man has today been charged with the offence and remanded in custody to appear before Bedlington Magistrates’ Court on January 4.
Supt Jonathan Bensley, of Northumbria Police, said: “This incident has understandably caused concern among residents and has left a man with life-changing injuries.
“We do believe that this is a case of mistaken identity that has taken place while the victim was repairing a window in his role as a council employee.
“There is no place for violence in our communities, particularly when a bladed weapon has been used to inflict serious injuries on a victim.
“I would like to thank the community of Alnwick for the way they have come together and supported officers at every step of this investigation.
“Incidents such as this are very rare in this area and we hope our swift response offers some reassurance to residents living in the area.”
Daljit Lally, chief executive of Northumberland County Council, said the victim is receiving the support of the council and police at this time.
She said: “We were saddened to hear of the attack which took place on a member of our staff who was attending an out of hours call on the weekend. We are supporting him and his family at this time.”
Anyone who can assist police further is asked to call 101 quoting log 932 261220.