Glow-in-the-dark switches were available overseas, he said, but were expensive, and meant replacing the entire switch cover. His solution was to produce stickers from photoluminescent vinyl which fitted neatly over a switch.
He was applying for a patent, and hoped to sell his product via The Warehouse.
Second in the judges' awards went to #InstaHealth, a company from Kaitaia's Abundant Life School that promotes healthy food and employs a Maori business model.
Team member Brenda Dos Santos said their meals contained kai, such as pork and watercress. The company was involving whanau and raising awareness of the need to eat well.
The meals contained no artificial additives and came with information about their calorie content.
Springbank School's Cashew Company was third in the judges' awards and won the customer choice award. It imports cashews from a mission station, providing employment in Mozambique, and turns them into a peanut butter-like paste at a Northland macadamia processing plant.
The product's branding is based on the Mozambique flag and team members dressed in rasta colours with beanies and false dreadlocks for maximum effect on Saturday.
Second in the customer choice award went to Innoluminate.
Scheme co-ordinator Gary Larkan said the Top Energy-sponsored fair was "all about selling".
"If you had kids sitting around doing nothing, they're not going to score highly, no matter how pretty the stall looks. They've got to engage with the public and be enthusiastic about their product," he said.