It is a strange construction, isn't it? It sounds kind of folksy and old-fashioned. As a native speaker, I'd understand this, but would certainly put it in the category of "non-standard" English. Perhaps it's the sort of thing that country folk in some rural areas of the US might say?
One thing is certain, though: you really don't need to worry about it. You'll probably never come across this construction ever again.
But here's some advice that's more useful:
Don't write 'smth'. It really isn't a word. For some reason, Russian learners of English seem to think that 'smth' is a standard abbreviation that you can use in any written context. Believe me, it isn't. In fact, it's weird and confusing. Just write the normal word : "something" - it only takes a few extra seconds.