According to Andrew Dudley of Haighteration, "Every once in a while there's this creepy train whistle sound that blasts through the neighborhood, usually at night. Of course there are no trains over on this side of SF, so it's pretty mysterious."

His neighbors and a few commenters (residents ranging from Western Addition to the Sunset to Noe Valley) also claim that they've heard this mysterious whistle. Spooky, indeed.

Do you know what said sound is and from where it emits? If so, you could win a fashion-forward t--shirt. "The first person to send us definitive proof of the source of this sound will win themselves a very sexy, very rare Haighteration t-shirt," declares Dudley.

Our guess? Something janky with ShotSpotter, perhaps? Just a shot (tee hee) in the dark.

Read all about it at Haighteration.