Andy Griffith in the early 1990s sold many of his personal effects and memorbilia that had been given to him over the years.  Some were souvenir keys to various cities and police and sherrif departments that were given to him when he visited a particular place.  He would be handed a key or mini-badge etc. and then would pocket it and probably it was put in a dresser drawer.  He also sold things like books from his personal library some were ones he bought himself others were gifts from authors.  In each case he hand signed a certificate of authentcity that was countersigned by Don Britt who was manging the sale. There were scores of items that were sold originally.  From time to time pieces appear on eBay.  These are not to be mistaken for "props" from the show.  Most, if not all, that Andy Griffith himself kept were intrusted to his good friend Emmett Forrest for his collection now housed in the museum.  The COA's are actually a good way to get an authentic Andy Griffith autograph outside of a personal check. 

Below is a very high quality handblown and cut pitcher and glasses set that belonged to Andy Griffith.  The pitcher has his full name and the glasses have "Andy."