While driving back from the hamfest, I decided to try 87.7 and 87.9 FM, hoping I might hear a pirate. Instead I heard what sounded like two commercial stations on 87.7. One was fading in and out and was in Spanish, the other was a Christian station in English, with an ID of Wow 101.5 (or was it Wow 105.1?). I did a little searching online, and could not find anything that sounded like that station. We've had a bit of FM DX lately, so it could have been some distance away. I am not even 100% sure about the Wow part.
I know there's a few licensed stations that are on TV Channel 6, the audio frequency (87.75 MHz IIRC). And there are two in the DC area, so maybe the Spanish station was one of them? The other one could have been a translator of a regular FM station I guess, but again I can't find anything. I am not hearing it here at home, but I do not really have a proper FM antenna. Next time I am in the car I can try again and see what I hear.