Lots of people hear the voices and take them to be dead people asking them to do something.

There may be a scientific explanation for Force powers (but not lifeforms living inside all cells unless they are a very exotic form of life that aren't built on cells themselves) and belief in something isn't the same as something actually existing.

We don't know how lightsabers work (plasma blades contained inside a force field might be possible for a civilisation capable of faster than light travel).

No sound in space but there would still be sound inside ships caused by shock waves travelling through space.

So it's possibly doable, if someone wants to.