Sentence 1: Tim thought he saw a ghost the first night in his new apartment. 
 Sentence 3: He heard a noise and turned around 
 Sentence 4:  He saw what he thought was a fast shadow move across the wall 
 Sentence 5:  He still doesn't know what it is 
 Option 1: It was the middle of the night and he was watching tv. 
 Option 2: He thought maybe he had dreamed it.