I saw it in Miley Cyrus Fugue in measure 88 between the 3rd and 4th beat for the right hand. It's being reached at 2:42-2:43 in the video and I don't hear anything special. Here is a screenshot for convenience:
If you listen to the recording, the melody voice in bars 88-89 really goes f f f g g g ees c' | g ...; this is probably a way how the author wanted to present this fact, using voice/staff switching lines.
It would have been actually better to use the proper notation of the leading voice: