Hey WF, another question for you that's probably more obvious than I'm making it out to be:
"Is using twins, most often identical twins, a cliché in terms of writing?"
Think about it -- your MC just lost his/her friend, or their going through all living hell because their loved one just died, whatever. Then, bam, they 'see' them again; thinking it's a hallucination (or a miracle). Nope, Chuck Testa just their identical twin trolling their lives!
I think it's kind of a gray zone in a way, because you never actually read books like that. Or, at least, no book I've ever read. Even so, doesn't it seem kind of childish? That they had an identical twin that you mistook for them (even more so through a moment of dire need) for someone else? It's possible, but at the same time somehow unlikely.
Am I making any sense here? This isn't the first time my mind's attempted to squeeze identical twins into a plot -- but is it acceptable? Do you think that it can be used as a genuine 'plot twist'?