If you tap rapidly on switch you can produce infrared radiation at about 400 GHz. You will never can do Light in both EC and real life from LC circuit!
Our Visible Light is electromagnetic wave after Radio waves, Microwaves, Infrared radiation. Theoretically you can produce that waves of light with an LC resonating circuit, but you can't produce such L and C components! You even can't simulate here.. For above given values (minimmum available in EC) of L=1pH and C=1fF, the circuit must theoretically resonate at about 5033GHz=~5THz in Infrared radiation range but not more.
Radio frequency spectrum:
http://www.tvtower.com/images/rf-spectrum.jpg
(sorry for my bad english :p)
