Two Christchurch electricians have been dealt hefty fines for unauthorised and dangerous electrical work.

They've been caught in the Electrical Workers Registration Board's latest sting on unsafe work.

Aaron Ray's been ordered to pay nearly $3,500 for failing to disconnect power to a house he was demolishing. .

Marcin Sztandera has been ordered to pay over $1,000 for doing work he didn't have the ability to undertake.

Registrar John Sickles says the public must understand bad and faulty workmanship can be fatal.