Like the electrician who was asked to blank off my cooker while we did kitchen renovations. He rocked up, a day late, switched the oven off at the wall, and proceeded to cover the end of the power cable with earthing type sticky tape. It was left like that.
Meantime I went to the main power source and turned off the mains electricity. The other workman told me I was over-reacting as the electrician "knew" what he was doing. The evidence denies that, and he never came back. Might just have been because I mentioned I used to sign off works for grant aid, I genuinely needed to know how he intended to extend the electrical system, but he wasn't happy to explain anything.
The one who eventually did some work managed to instal a faulty 30amp switch and a wall switch non compatible with the lighting system, he refused to return unless I paid him again. I will have to do it myself!