Haunted bathroom

I was peeing in the ladies' room during a party at St. Mary's Outreach Center on Roland Avenue in Baltimore.  It was night.  I was alone.  The bathroom was a two-staller.  I heard the bathroom door open and the door of the stall opened and the stall walls wiggled.  I heard footsteps and the slight swish of fabric rubbing against itself.  I heard water.  Nosy, I peeked under the stall to see if the noise was a girlfriend but there were no feet.
"Hey!"  I called.  Nothing.  I bent over and the stall was empty.  "Hey!"  I called.  I'm being really human here!"