A fault in the earthing system outside a Perth public housing property likely caused an 11-year-old girl to suffer a life-threatening electric shock from a garden tap, WA's electricity regulator says.

Denishar Woods is fighting for her life at Princess Margaret Hospital after touching the outdoor tap at her family’s Beldon property on Saturday night.

EnergySafety director of electricity compliance Mike Bunko said the fault was likely an upstream “open circuit neutral”, which could be caused by corrosion, a loose connection and in some cases, poor workmanship.

Mr Bunko said residual current devices would not protect against an open circuit neutral.

“The fault is preceding the RCD,” he told 6PR radio on Monday.

“If you get a fault upstream, generally before the meter where the electricity is coming in, the RCD can’t see it and can’t operate.”

WA housing minister Peter Tinley said the Department of Housing was looking into the incident and cooperating with Energy Safety, which is undertaking an investigation.

“We will get to the bottom of this,” Mr Tinley told reporters.

“We just hope that she pulls through.

“This is a tragedy that nobody should have to endure.”

Mr Tinley said the family would be immediately accommodated elsewhere if they didn’t want to remain at the property, where the power has been cut off to make it safe.

“If we have to put them in a hotel or a motel, then we’ll do that,” he said.

“Clearly, they wouldn’t have a lot of faith in the property. They won’t be expected to move back into it.”

He said he was not aware of family’s claims they had complained more than once about short-circuiting.

Mr Bunko said open circuit neutrals were less common in new houses because they had a lot of plastic pipework.

“If you do get electric shocks off taps or you notice that your lights are dimming for no good reason, then you need to report it to the network operator,” he said.