A 49-year-old homeless man was found dead behind the old post office on South Auburn Street in Grass Valley Wednesday morning, possibly due to alcohol. “He is somebody that we’ve known to be homeless,” said Cindy Maple, executive director of Hospitality House, the area’s leading shelter and services provider. “We have had recent interactions with him.” The man’s identity has not  yet been released, pending notification of next of kin, authorities said. Because the man was covered in blankets and bottles were found near his body, it is presumed that the man died of alcohol-related issues and not by exposure, …