Baltimore’s homegrown theater scene continues to explode with new theater companies popping up all over town, bringing fresh blood to old and new neighborhoods. In the midst of all this growth stands the patriarch (matriarch?) Spotlighters, turning out new shows since 1958 when it was a project of the city’s Parks and Rec department before becoming an independent company in 1962. It can take a little looking to find this place, tucked away behind other buildings on St. Paul, but once you find it you’ll find a homey little theater house, cheap glasses of pre-show wine, and a cozy stage featuring local actors, many of whom, if the past predicts the future, will go on to even bigger things. And this fall they are bringing us “The Rocky Horror Show”—a classic put on by a classic.