RadioShack will reportedly close up to 500 stores in its latest attempt to overhaul a slumping business. The Wall Street Journal says the closures will come in the coming months, though its not clear which locations are in the crosshairs. RadioShack currently operates over 4,500 stores, so the retailer will still have a sizable US presence even after the cuts. The company has thus far struggled to reinvent itself and attract a new generation of customers; its latest try involved an 80s-themed commercial during the Super Bowl. …