Kitchen renovation including range hood, power outlets and electric oven.
Installed a 2.5m long heavy chandelier in a tall 2 story stairwell / entrance.
A 10mA power circuit setup installed in an ambulance powered by an inverter.
Cats under floors or in roof space can come in contact with live wires.
Dust bunnies in switchboards can allow current to track between potential differences and can sometimes cause serious problems like fires.
When gutters are full and it rains they can backwash into the eaves flooding lights outlets and switchboards. In this case it shorted out the main switch.