We don't know where it came from, which album it's meant for, or what Miley has got to say about it. What we do know is that a Miley Cyrus song called "Nightmare" has leaked and it is an absolute tune.
Miley embraces the electronic side on this track which many people are assuming is pre-Bangerz because of the production. That is a fair assessment considering that fact that the production sounds slightly dated. Perhaps circa 2009 or 2010.
Either way, we'd never look a gift horse in the mouth and "Nightmare" is still a banger of a track.