Last year I remember listening to a reviewer on NPR describe a
non-fiction book about the history of darkness. The thrust of the book
was the dramtically different way people behaved during the hours of
darkness before the advent of the electric light bulb. Also discussed
were the odd sleep patterns before electric light and the particular
danger from marauding bands of thugs in the lightless dead of night.
Have tried my hand at searching the Barnes & Noble site without success.

Greetings, Nautico!

I believe this is the book you want: 

At Day's Close: Night in Times Past 
http://www.amazon.com/gp/product/0393050890 

Here's an NPR program discussing the book: 

NPR: A Fitful History of Sleep
http://www.npr.org/templates/story/story.php?storyId=5225305 

If my guess is off the mark, I'll cheerfully go back to the drawing
board and try again.

Best,
Pink

Yes, Pink, that's it! Thanx!!

Thank you very much for the five stars and the nice tip!

~PInk