Were the Nazgul free from Sauron for the most part of the Third Age?

[Gordis]

Originally Posted by CrazySquirrel

And yes, has anyone an idea how an invisible nazgul can make himself look normal. Seriously I mean. Is it possible if he has his ring? And if he hasn't?

Sorry for the long delay with the reply. Actually I was hoping that someone else will have an answer for you. I am not so sure of mine, you see.

I believe that the ring permitted to shift a person from one word into another - from seen into unseen and vice versa. So, IMHO, with the ring on his finger and an appropriate spell a nazgul can easily be seen and even pass for a mortal. Perhaps shifting into physical word they even regained normal human sight?

Now what happens to a nazgul without the ring? That is the situation we see in LOTR and the Hunt for the Ring. By default the ringwraiths lived in the spirit word. Without the ring they were unable to be seen “ unclad” i.e. without normal (physical) clothes, hoods and masks that they needed “to give shape to their nothingness”. But on the other hand, their bodies were physically existent in the physical world, though invisible. Otherwise how could they wear the clothes, wield weapons and ride horses? That is where I am confused. All this seems contradictory to me.
Actually I wonder: can one bump into an unclad and invisible nazgul or will one pass right through?