Welcome! First things first: what country are you in? The Device selection does vary from region to region.
If you’re in the US or Canada, you have quite a few choices. The following thread covers US/Canada light switches starting around post 40. ( this is a clickable link)
If you’re in the UK, unfortunately at the present time there are no in wall sockets that work with SmartThings. I suggest you wait until November and revisit the issue, as Lightwave RF is coming out with their generation 2 shortly and it may change the options available.
LightwaveRF also has UK light switches, so again, you might want to wait until November. Or you can look at the other alternatives available now by starting in the following thread:
First things first: what country are you in? The Device selection does vary from region to region.