Possible Clues:

• Engage in legal proceedings
• It's quite legal so to have set fire to a gate, by the sound of it
• Contest at law
• How to deal with you in-laws if all else fails
• One will have to go to law to have set fire to one way in
• Sue illuminated one's entrance
• Go to law enflamed, facing one sort of barrier
• Sounds as if one may have set fire to an entrance and go to law over it
• Sparked off one lot attending to take action
• Sue brightened up one entrance