The lead should be cut off before the box was thrown away to prevent it from being used again.
Boxes should also be replaced if plugs were loose and no longer fitted snugly.
''If it's too easy to plug in, then it risks becoming faulty,'' Bain said.
Overloading was not the cause in this case because only two sockets were in use.
However, overloading a powerboard by plugging in too many appliances at once was also a fire risk to be wary of.
The Ōhaeawai blaze was only of many for Northland firefighters during the weekend.
In the Far North alone they were called to three crashes — one of them, in Broadwood, resulting in serious injuries — involving cars rolling. Alcohol was thought to be a factor in at least some of those incidents.
Other callouts were related to people lighting fires despite a total fire ban in place across Northland since March 11.