Compliance officer Richard Lamb said electrocution and fire were very real dangers.
He said the internet attracted sellers who had "limited knowledge of the safety around electrical products. It's become a huge problem".
Table lamps, circuit-breakers and travel adapters were the most high risk, followed by electric blankets and kitchen appliances, including toasters.
Lamb said he was also concerned with dodgy electrical goods being flicked off through daily deal sites.
He recently ordered a recall of 1700 travel adapters bought on one site, after an investigation found the products were not safe.
Electrician Andrew Ross said products bought without a compliance certificate could also put a person's house and contents insurance in jeopardy.
"I send my clients to specialist shops," he said.
"You will pay more but you know the shops are prepared to put their name to that product.
"It's just not worth the risk."
Despite everything, the allure of an online bargain can prove irresistible.
The Herald on Sunday spoke to a mother-of-two who said it was a stroke of luck that she did not end up with a dangerous lighting fixture in the living room of her brand new home.
"We initially looked at specialty shops but they were so expensive, it was outrageous.
"The architect had specified one that was $7000.
"This one was around about a tenth of the price and it looked exactly the same," she said.
Because she was building a new home, electricians were involved and they told her that the light did not comply with New Zealand standards.
"Usually we would have installed it ourselves, so we were really lucky," she said.
"They [the trader] were prepared to let us take it home and put it in our brand new house.
"It's not just insurance. We have two little children. If something had happened, we would have never forgiven ourselves.
"I would hate to think someone else has bought it and has it in their house."
Trade Me trust and safety manager John Duffy launched an investigation into the seller after the Herald on Sunday brought it to his attention.
He said the seller would be blocked from the site if they could not provide the necessary documentation.
Although listings were monitored, Duffy conceded that not every listing was checked for compliance.
He advised buyers to ask for a copy of the supplier declaration of conformity before making a purchase, a view backed by electricians.
