Two northern El Paso County fire districts have agreed to begin talks that could eventually lead to some form of consolidation.   The Black Forest Fire/Rescue Protection District and the Wescott Fire Protection District are next-door neighbors.   The Wescott Fire Department serves about 6,500 homes in 20 square miles.   Black Forest Fire/Rescue serves approximately 3,500 homes in a 48-square- mile area.   For years, the two fire departments have fought fires together under an automatic aid agreement.   Both boards of directors now want to know whether a closer legal relationship could benefit the citizens of both districts.   After several months of preliminary discussions, subcommittees reported that some form of consolidation might reduce citizens’ tax payments, as well as improve efficiency and flexibility.   But they caution that it’s too early to say whether the best solution would be a full merger, or creation of an umbrella authority to oversee the administration of both fire departments.