These are mystery/detective radio programs.

6 are Sherlock Holmes and Watson episodes featuring Basil Rathbone and Nigel Bruce. One cassette featuring a Holmes broadcast 

from 1939 has never been played. The other 5 used Sherlock tapes are from 1940-1948.

There are 5 cassettes from a program called "I Love a Mystery" with 3 sleuths solving mysteries {Jack, Doc, and Reggie}. They are from 1949 and 50 broadcasts . There is a 2 part audio cassette of theirs that has never been played called "The Temple of the Vampires"still in plastic wrap. And loving the bats on the cassette cover.

There is also 1 cassette  from the radio program "Philo Vance"another mystery detective.