This is a two part question, with the two parts being mirror images to each other.
Is the ability to use the Force a requirement, for some reason, to using a lightsaber? And if so, why?
And on the other side, on Hoth, when Luke is hanging in ice in the wampa's cave, he uses the Force to bring his lightsaber into his hand. But, as best I can remember and find, the Jedi always use a lightsaber like a "real" sword and keep it in their hands (although I think there's one case in a movie where a lightsaber is thrown to cut down support for a walkway). Can a lightsaber be wielded with the Force only? For instance, when Anakin's hand was cut off, could he have controlled the movement of his lightsaber the way Vader did with the objects he Force-tossed objects at Luke in the Cloud City?
While that's two questions (that I think are closely related), another way to put it might be to ask, "How closely is the use of the Force related to wielding a lightsaber?"
Addendum: No, this is NOT a duplicate of Do Non-Jedi (and Non-Sith) Use Lightsabers?. Note I am the one who asked both questions. I asked both because they cover different groups.
See the Venn diagram. I allow room for possible members of Sith and Jedi who do not use the Force. (Hey, in the Star Wars universe, almost anything can happen.) If that is not possible, then just imagine the black box not intercepting either or both of the Jedi and Sith boxes.
One can be non-aligned (with Jedi or Sith) and still use the Force and it's possible, at some point, we may find some odd story about a Jedi or Sith who cannot use the Force. (There may be some story about how such a person is not felt by Force users, so is valuable to one side or the other.)
This question overs the black box. The other question covers the green box. Yes, there is overlap, but there are also distinct separate groups covered by each question that are not covered in the other question.