A firefighter on Staten Island was arrested Wednesday for allegedly selling $40 worth of weed to undercover cops who spotted his advertisement on Craigslist. During the transaction, 32-year-old Michael Seise, a three-year veteran of Ladder 82, also inexplicably hinted that he was a member of the FDNY, a police source tells the Daily News, adding, "This guy is an idiot. There's really not much else to it." After the arrest, police found traces of white......