GB wrote:
These Sonoff switches are tiny, and the terminals are stupidly small.
I'm more concerned, though, that the whole thing has a clip on plastic
cover. If this falls off, the terminals are exposed.

Should I just return them as unsafe? If I do, does anyone have
recommendations for some switches that are a bit better made?

I think these are made for a global market which largely has lower expectations
of electrical safety. However I recently installed some Ikea lights that
have a similar kind of arrangement (clip on plastic cover with lever
terminals inside) and it looks OK to me - it would be hard to accidentally
come into contact with mains.

Are the switches going to be situated somewhere where the cover falling off
might result in someone touching the terminals? For example, if the switch
was mounted on top of a kitchen cupboard it seems unlikely that unsuspecting
fingers would get into it. If this is a real risk, you could mount it
inside a secondary enclosure (eg a surface pattress).
You can also get enclosures suitable for them:
https://www.ebay.co.uk/itm/Quality-I...e/353210911659

Theo