Where to find light sword for Dragon Fable

It's best to consult the Weapons section of the DF Encyclopedia on the forums. At the top of the list of threads are stickied topics you'll need. "Best Weapons for your Level and Class" is the most useful sticky for you, while the "Weapons Sorted by Power" is more useful for finding an alternate weapon to one named in the BWfyLaC thread, such as if the named weapon is difficult to obtain. If you know the name of a particular weapon you want, the non-stickied threads are each for individual weapon or weapon series, and it may be in the A-Z Weapons List.

Link to the DF Encyclopedia - http://forums2.battleon.com/f/tt.asp?forumid=256
Link to the weapons section of the DF Encyclopedia - http://forums2.battleon.com/f/tt.asp?forumid=119
Link to "Best Weapons for your Level and Class" - http://forums2.battleon.com/f/tm.asp?m=17074502
Link to "Weapons Sorted by Power" - http://forums2.battleon.com/f/tm.asp?m=16300750