My headphones record properly. And Audacity records sounds played on my computer properly. But it also is recording sounds through the headphones. If I tap on my headphones, it gets picked up. I shouted an obscenity today that got recorded, even though I do not have a microphone. Audacity is treating my headphones as some sort of reverse microphone.
Is there any way I can stop this 
??? Thank you.
even though I do not have a microphone.
Are you using a laptop? Most laptops have a built-in microphone.
No. There is absolutely no microphone. The headphones do not have a microphone. But if I say something into them, Audacity will record it (although with a very low gain).
SOLVED
I went to Realtek HD Audio Manager. Right-clicked the picture of my audio input/output jack. Chose “connector retasking”. Switched from “Front Speaker Out” to “Headphone” (which I am using). That fixed it. Not sure why though. Hopefully this helps anyone else.