Possible Clues:

• Opera interrupter of note
• Lloyd-Webber hit, for short
• Not really there
• Henry appears in Christmas show, with, initially, Marley's ghost
• Eerie figure
• Orphan Tommy's part is non-existent
• Face Thomas outside hospital, a shadowy figure
• "The __ of the Opera"
• Ghost in Hampton wandering about
• Halloween scarer