Microwave (Muirhouse EH4)

Delonghi combination microwave. It works well but when it's switched off occasionally a very faint short duration scratchy sound can be heard. I don't know what it is but it's making me feel nervous. I don't want to take it to an electrician and run up a big bill so I've decided to get rid of it. If you know what you're doing with this kind of thing then you're welcome to come and take it away. It also needs a good clean. (sorry)