Hope it gets sorted, I cringe at the stuff my dad does, yeah he makes me cringe hahaha!
Insulation tape? thats for nancies, I just twist the live conductors together and leave them apart while I test another bit of the circuit! Can't be arsed wiring up a plug? Just find another appliance with one and twist your bare conductors around the plug and insert into socket!
When "We " are doing electrical stuff round his house, he spends all his time doing that stuff and I just go quietly and terminal block all his connections or at least put insulation tape on them till we finish testing stuff. Watching him wire up a light fitting while standing on a rickety ladder when its too dark and he can't see to well without his glasses is "funny" well not if he falls on me any way.