Over 70 percent of electric blankets were found to be faulty at a recent safety event in Manton, including a blanket that was believed to be around 50 years old.
Older and disabled people were offered the tests as part of a winter safety initiative by Nottinghamshire County Council's Trading Standards team.
Anyone who had a faulty electric blanket was given the chance to exchange it for a brand new replacement.
Faulty electric blankets have directly caused nine house fires in Nottinghamshire since April 2009, all of which could have been prevented.
Blankets fail the test for a number of reasons, including their age, worn fabric, faulty controllers and crossed wires.
People should replace electric blankets at least every ten years.
Councillor Mick Murphy, Chairman of Nottinghamshire County Council's Community Safety Committee, said: "Thanks to our Trading Standards officers we have found that many people are complacent with electric blankets and still use them for decades without a second thought.
"Electric blankets can be potentially deadly so we encourage people to get them checked regularly and buy a new one after ten years of use."
People wanting their blanket tested should contact Trading Standards on 01623 452 005 to assess demand for future testing events.