Updated UA "City of Light" - removed old effect and replaced with "In your Capital, whenever you build a World Wonder with any Great Work slots or a Guild, gain one free cultural Great Person that matches the type of slots or Guild."
Note: You only get 1 free Great Person regardless of the total number of Great Work slots in the wonder. If built in the capital, this happens once for each Guild, and once each for the following 8 World Wonders: Great Library, Parthenon, Globe Theater, Sistine Chapel, Uffizi, Louvre, Broadway, Sydney Opera House.
This will only give you a Great Person the first time you build each Guild. You can't gain multiple Great People by selling and rebuilding them or having them conquered and rebuilding them in your new Capital.