Ultrasonic/electronic mouse repellants? anyone used them?

[balancingact]

saw a mouse skidding in our kitchen, nearly fainted. googled mouse repellants and saw these things you can plug in sockets and electronic and ultrasonic "stuff" repels the mice? is this a scam or has anyone used them and found them effective?
i'm desperate and the thought of putting down mice traps makes me feel faint.
thanks

We use them - the type where you can change the electronic frequency to constant or intermittent - which stops them getting used to the noise.

You can't use them if your DCs have pet gerbils/hamsters etc. Dogs & cats are OK.

It drove the mice out of the living spaces of the house although they still live under the roof tiles.

I used them against rats. Trouble was the rats shit themselves at the noise and I had a terrible mess to clean up in my outhouse. They skiddadled next to my neighbour's outhouse instead