The prosecution was the 13th brought by the Board over the past twelve months.
The conviction followed Kyle Mack pleading guilty in the Whangarei District Court on March 17 to five charges of performing unauthorised prescribed electrical work.
The charges related to five separate occasions between October 2011 and March 2012 when Mack performed unauthorised prescribed electrical work alongside repairs and maintenance of refrigeration equipment at a local butchery and farm, Mr Sickels said.
Mack was fined $2000 and ordered to pay reparation of $1360 plus court costs.
Meanwhile on May 2, Classic Horse Coaches of Dannevirke was found guilty in the Dannevirke District Court of doing unauthorised prescribed electrical work.
The company was also found guilty of intentionally or negligently carrying out gas-fitting work in a manner which endangered life, Mr Sickels said.
"The defendant carried out gas-fitting and prescribed electrical work on custom horse trucks in 2010 without being authorised to do so.
"He was fined $23,000 for the gasfitting work and ordered to pay solicitor's costs and court costs."
The Electrical Workers Registration Board was established in 1992 and is responsible for monitoring more than 30,000 registered electrical workers.