No, by definition.
If something is "super"natural, that implies something beyond nature. But in that case, would that thing itself not be part of some larger nature as well? Just because you're stuck in a box, that doesn't mean the world outside the box is supernatural.
Or, if something is labeled "supernatural" simply because it is not understood, then you could apply "supernatural" to electricity, spacecraft, internal combustion engines, airplanes, and modern medicine. The sentence "I don't understand this" would be the proper thing to say, if anything, and not "This is supernatural!"
I also know that the human mind is capable of hallucinating/imagining things at the drop of a hat.