“Adventure wanted. Will go anyplace, do anything. Write Box 13.” That’s the newspaper ad Dan Holiday runs and each week a new letter brings him to the doorstep of danger. Holiday runs the ad to get plots for his mystery novels, but he has to survive each case before he can start writing. Big screen star Alan Ladd puts his film noir bona fides to work as Holiday in two old time radio mysteries: “Mexican Maze” and “House of Darkness.”