The reliable way to hire a tradesperson

Hi, I have extractor fan in the bathroom and have problems with it, whenever I switch the light the extractor fan suppose to work when the light on, but eventually it power tripped the whole power house. Electrician stated there spur switch has extractor fan wire and other wires that where connect which were not suppose to be .....how can we find the fault wires ?

I have some external lights, and wanted to add another light, but it requires an earth. Unfortunately, all the existing lights are two core, and there are no earth wires externally. I was thinking of adding an earth spike in the ground, but would appreciate a recommendation as to what is required, and the earth cable capacity recommended if it is "just" for one or two lights? I was thinking an earth spike, and earth cable capable of handling maybe 10Amps, or am I woefully wrong?! And apart from the cable, what are the "right" additional parts to make the earth legitimate? Many thanks,

I need to build a media wall who do I contact for that kind of wirk