Does anyone really feel safer seeing this old fart on the subway? The city on Sunday saw its sixth and seventh subway slashings in less than a month — and the terrifying spree has inspired the Guardian Angels to resume patrols not seen since the Big Apple’s bad old days. For the first time since 1994, the red-beret-wearing Angels will maintain a regular night-and-day presence in the subways, group founder Curtis Sliwa said. The teams of 12 volunteers will take two shifts, one running from the afternoon until 7 a.m., and the other from the morning into the afternoon. “Riders are coming up and asking us: ‘Please, you’ve got to come back in force,’ ” Sliwa, who founded the group in 1979, told The Post. “I think it’s become obvious that the police need help, the MTA needs help. They can’t handle it.” Two men were slashed on Sunday, both in Manhattan. Colwin McGregor, 31, was attacked around 3 a.m. on the southbound 2-train platform at West 110th Street and Lenox Avenue, police sources said. He had gotten into a fight with a woman, who summoned another man to slash him in the face with a sharp object, although no weapon was recovered, the sources said. McGregor was taken to St. Luke’s Hospital and later released. Then, at 9 p.m., a man was slashed in the hand during a mugging on a C train as it entered the station at 155th Street and St. Nichols Avenue. The robber cut the victim with a knife when he refused to hand over his wallet and cellphone, sources said. The thug fled, and was still at large early Monday. The victim was treated for minor wounds at New York-Presbyterian Hospital. Police Commissioner Bill Bratton said Sunday he’s not surprised residents are on edge over the slashings. “New Yorkers have a right to be alarmed or concerned, particularly those riding the subways,” he said. The incidents do not seem related, Bratton said on John Catsimatidis’ 970 AM radio show Sunday morning. He pointed to crowded trains and mental illness as possible causes. Bratton is getting help from quarters other than the Guardian Angels. Late last week, the National Guard, which has patrolled city transit centers, including Penn Station, since the fall of 2014, established a presence in the Barclays Center subway station in Brooklyn, site of a slashing last week.