Possible Clues:

• Exist essentially? Not out there!
• One reply to "Yoo-hoo! Where are you?"
• Beckoning words
• 'Come to this room!'
• 'Let's hide out!'
• Response to 'Anybody home?'
• Vague response to "Where are you?"
• Possible follower of 'Psst!'
• "Where are you?" response from a nearby room
• 'Where are you?' response from a nearby room