Related Clues:

• In the tube a constant light
• Light opening to exhibition held by artist
• A trick? Be first to give a signal
• Very light head inhaling carbon monoxide
• Warning from company employed by head
• Experience life in prison -- that can be a warning
• Serve inside presumably as a shining light
• Warning or guiding device
• Highlight of historic communication
• Exist as a prisoner, a guiding light
• Fire man of the cloth, getting bishop as replacement leader
• The Bat-Signal, e.g
• Signal how to dupe people?
• Signal rise in English meat sandwiches
• Warning - it could be a swindle