I don't remember when I read this. At least 20 years ago but maybe more. Nor the length. Probably not a very short short story but whether a novelette or a full length novel I have no idea.
It was at the same time SF and fantasy, because the only thing I remember is that one of the characters, while in a spacesuit in the vacuum (SF!) was able use his "phantom-hand" (Fantasy!).
I think that at some point he had lost an arm and developed this strange telekinetic power which he interpreted as a "ghost arm". Later he was grafted an artificial arm, but retained his telekinetic power as a "third" arm that could penetrate matter and for instance wipe his sweat from his brow while in his space suit. I don't remember anything more, alas.