Who was the old man?

[The Might]

Ah, alatar, now I understand what you meant. I thought you were asking whether Saruman was known to have had such power before or afterwards, but I see you meant it generally as in the history of M-e. In which case of course there had been others who deeply knowledged in the dark arts used them to conjure up "phantoms".

Take the Barrow-wights raised by the Lord of the Nazgul as a best example not to mention the deeds of Sauron during the First Age.

Actually, the phantom could well fit the characteristics of a wraith as described elsewhere by Tolkien, clad in this case like Saruman and not with some dark cloaks like the Nazgul.

What I am saying with all this is yes, there was a precedent so there is no reason to think that it was no longer possible - the Witch-king had done it like what, a couple of months before?

And you also bring up Occam's razor, something I would rather object to. Why? If we were all judging by this priciple probably a lot of the threads on the forum including this one would not have existed. I would have believed it was Saruman and not questioned it.

And even so, Occam's razor does not necessarily mean that the simplest answer is the right one:

This is often paraphrased as "All other things being equal, the simplest solution is the best." In other words, when multiple competing theories are equal in other respects, the principle recommends selecting the theory that introduces the fewest assumptions and postulates the fewest entities. It is in this sense that Occam's razor is usually understood. This is, however, incorrect. Occam's razor is not concerned with the simplicity or complexity of a good explanation as such, it only demands that the explanation be free of elements that have nothing to do with the phenomenon (and the explanation). ~ Wikipedia (yes I trust Wikipedia)

Now I do not believe that the idea that it was communication through thought as seen in Ósanwe-kenta or that it was a conjured-up phantom using or not using the forged Ring for that purpose have elements having nothing to do with the phenomenon. They both explain how it could have been possible for the old man to appear and then suddently disapper.

Although I agree that your idea is most likely, the others are plausible and should not be discarded that easily. I was not looking for a clear answer in this thread, I doubt one can be found, what I search for is alternatives.