This is a new DELCO REMY (GM) dimmer switch . It is an OEM NOS DELCO REMY (GM) switch, not an aftermarket replacement.  The part number is 1997026 (D802) , it is in group # 2.459 of the GM parts catalogs . It is unused and has been on my warehouse shelf since it was purchased from GM. The part has 4 slip terminals & is stamped DELCO REMY on the body. Some of the listings are listed in the photos.      

According to GM  It  fits:  1959-1960 GM CARS w/ AUTRONIC EYE         

The part number may have been later superseded to fit other models, but this is the only correct application in the original listings.

I am selling more than one of these same items, so the pictures shown may not be the actual item you receive.