If he were to tell his wife, Sasha, then... is correct but the rule doesn't just apply to names.
E.g. There are fourty-nine people, I think, that do....
Use this when you want to add extra detail - The sentence could read: 'If he were to tell his wife then...' but you are giving extra detail about his wife, i.e. her name, so that's why you need the commas.
Nothing, I'm all set with this question. I think I knew the first one was correct, but I just LIKED the second one. I read it in a slightly different context (in a paper I'm editing) and it just seemed so right.
From the Chicago Manual of Style:
5.49 Unless it is restrictive (see 5.50) a word, phrase, or clause that is in apposition to a noun is usually set off by commas….
The leader of the opposition, Senator Darkswain, had had an unaccountable change of heart.
Jeanne DeLor dedicated the book to her only sister, Margaret.
My wife, Elizabeth, had written to our congressman.
5.50 If the appositive has a restrictive function, it is not set off by commas:
My son Michael was the first one to reply.
Walpole had borrowed the rusty bread slicer from his friend Teetering.
So you decide on commas based on whether you believe your usage falls into 5.49 or 5.50.
I like 5.50 for If he were to tell his wife Sasha, then...
But I can see where others would like 5.49 for If he were to tell his wife, Sasha, then...
Okay, in this context, only 1 and 2 are correct. Since the sentence begins with an if clause, a comma must follow Sasha (so the third one is out). Since Sasha can be considered parenthetical, a comma can precede Sasha too.
I have just come to realize that "If he were to tell his wife, Sasha, then..." might be using Sasha for direct address. In other words, out of context, this sentence might not be saying his wife's name is Sasha but that the speaker was addressing someone named Sasha. (Is Sasha a man's name or a woman's name?)
In "If someone were to tell his wife Sasha that..." I would assume that the person in question was in favour of polygamy or lived in a society where a man can have more than one wife. Without a comma there is no apposition.