The audio files of radio shows that I post on this site are believed to be in the public domain. I do not own the copyright to any of the shows posted on this site. It is believed that these shows do not have copyright protection. There are numerous other sites with similar notices that offer audio files of these shows for free as well. If you feel that one of the shows that is posted here is protected by copyright then please contact me and I will remove it.
Here are some places on the Internet that offer free old time radio shows:
The Internet Archive has every episode of Escape and Suspense available for download.
OTR Network Library A treasury of free radio downloads.
Zoot Radio Requires signing-in but the services are free.
You can also find a long list of sites offering free downloads at this website, OTRDays.com. Most of these sites are about Old Time Radio in general. A few are devoted to specific genres or specific shows. As you can see there are numerous sites offering free downloads, information and discussion forums about old time radio on the Internet.
There are also Old Time Radio subscriber services where for a nominal monthly fee you can access thousands of shows and download as many as you want. The fee is to cover the costs of providing the website and service, not for the shows themselves because they are believed to be in the public domain.
Last but not least, is Ebay where there are numerous people selling their collections of Old Time Radio shows under the premise that these shows are now in the public domain. You can buy DVDs that contain the entire collection of shows for a radio series at a reasonable price on Ebay.