Well this might give you a laugh,
Years ago I went for a job at the old British Telecom, I sat the English test and the maths test and felt I had done pretty well then I went before three people for an interview and again I thought it went ok, the final thing they asked me was to wire up a bell with a battery and a bell push like you have on the front door and when you push the bell push the bell would ring. Simple you might think as I did ( I had served my apprenticeship as an instrument engineer). Anyway I don't know what happened as I had a complete mental block and pissed around trying to get the bell to ring, it either rang all the time very loudly or didn't work at all,I was getting more and more flustered and kept cocking it up, finally I wired it up so the insulation on the wires started to melt and the whole room was filled with acrid smelling smoke. One of the interviewers then put me out of my misery and said that they had seen enough as he rushed to disconnect the battery and open the window. I was embarrassed to fuck as I mumbled something inane and left with my tail between my legs.
As soon as I left the room It came to me of how I should have done it.
Surprisingly I never got the job.