Please give me as much help to find this song as soon as possible >:|?

I just remembered a song I used to like so much some years back...
maybe 4 years back. I can't remember a tune or any guaranteed lyrics,
but during the chorus I do believe there are the words "What happened
to the ghost that...... something something something."

A guy sings it and it's theme is kind of sadness (just how the lyrics
are), and I think I remember it's to do with not being with a girl
anymore.

I know that's hardly any information at all, but if you give me names
of what you think the song might be, it'll just click when I read the
right one.

Please help! Even when I was listening to it years ago, it wasn't a
brand new song.