I've seen circuits on a room by room basis in Thailand rather than split into lighting and power circuits. It's okay for most as long as 2.5 is used throughout, although kitchen and bathrooms have separate rules.
I guess no rcd (critical) and isolated via cb not main consumer switch. However, I have seen the main power supply run through the roof to the consumer unit, which is a real gotcha if you are unaware.
I never use the screwdriver test thingy. If I don't know the wiring, I pull out from the meter on the lampost, such is my trust in Thai electricians.