What does amir mean by "my life as a ghost"

Amir was always aware of Baba's judgments over him. Amir felt Baba appreciated Hassan's masculinity over Amir's weakness. Amir could never live up to Baba's expectations: he felt like he did not exist in his own house. Amir wanted to win the kite competition to prove to his father that he was somebody:

"I was going to win, and I was going to run that last kite. Then I’d bring it home and show it to Baba. Show him once and for all that his son was worthy. Then maybe my life as a ghost in this house would finally be over."