That bluish glow may, in fact, be an indication that this figure is a Force ghost. We've seen in the Star Wars sequel trilogy that they are capable of interacting with objects, and it's not outside the realm of possibility that this particular Force ghost was moved to do so due to the importance of that particular object.
It's also worth noting that, while the face is obviously obscured, the dress bears a great deal of resemblance to your standard Jedi robes — specifically, those worn by Obi-Wan Kenobi, whose Force ghost instructed Luke to go to the Dagobah system to receive instruction from Yoda earlier in The Empire Strikes Back. He was also a guy who was endlessly encouraging Luke to follow his destiny, so we'll go out on a limb to opine that "follow your destiny" kind of sounds like something he would say.
Even if we're right about this, and we think we are, it still fails to address the question of just how in the heck Maz Kanata came into possession of the lightsaber so that she could pass it on to Rey during the events of Star Wars: The Force Awakens. It's a question that Marvel's Star Wars series will probably answer sooner rather than later, though — and this mystery Jedi/maybe-Force-ghost probably won't remain hidden from Luke for much longer.
Marvel's Star Wars #3 goes on sale on February 26, 2020.
