A faulty fridge light is being blamed for a network telephone problem in Wangaratta, in northern Victoria.

The network has been plagued by interference for weeks.

Telstra technicians used hand-held antennas to track down the radio frequency noise, that was causing widespread drop-outs.

They found static from a faulty light in a fridge was to blame.

Telstra's Max Jennings says the home owner was taken aback when told his fridge was causing the interference.

"I don't think he could believe that it was his fridge that was doing it," he said.

"But he was very good about it and once we disabled the light, the interference source disappeared.

"He can still have his cold beer."

Mr Jennings says an "enormous range" of rogue appliances can cause disruptions.

"There's things called mercury vapour lamps which are often used in retail premises, domestic TV installations is a big one, even large electronic advertising signs can cause interference," he said.