After she stocked the deep freezer and canceled the physical therapy appointments, there still remained the problem of the mail. At first, Shannon Huehlefeld would pick it up in a pair of hospital gloves — she keeps a box by the door — and thumb through it carefully. If she needed a letter immediately, she’d spray it with Lysol on both sides. Everything else she just let sit. The virus, she knew, can live on some surfaces for days. She’d been thinking about her vacuum, which has a light on its underside that’s supposed to sterilize the floor beneath it. Then, last ...