Possible Clues:

• Visitor is supposed to be announced
• Part of the inn crowd
• Plus-one, say
• Person who stops corporation circumventing employees' case
• Visitor's supposed to be heard
• Visitor suspected, reportedly
• "Be Our ___" (Angela Lansbury/Jerry Orbach banger)
• Invitee speculated on the radio
• Not permanent
• Person who's invited may be judged in hearing