as in ghost
producer, ghost songwriter, ghost writer (books)
etc.
that means when the person remains
anonymous or doesn't take credit for his/her work.
1)
Kanye "ghost-produced" for
rapper D-Dot before.
2) Ne-Yo ghost-wrote for Beyonce on her song Irreplaceable and everybody thought Beyonce had written the song.
3) Much of the later part of the children’s horror series Goosebumps was ghostwritten.