That looks like a couple of very old (probably worn out) VHF TV antennas. In it's prime the larger would have done well as an FM antenna.
I don't want to be critical of the photo, but I can't see the entire antenna, it's possible that it is a single 2-bay VHF... Electrically similar to the UHF panel antenna designs.
The twin lead wire probably rotted away in the sun years ago. Which is why you can't find any connection inside the house.
As I drive or walk around the neighborhoods here in the Seattle Metro area, I still see a few of that type antenna. Virtually all have been abandon since the 60's and 70's.