Calm Down!Is the peice of "Asbestos" intact and not coming apart?If so it is realitively safe to handle.You can carefully replace the unknown panel with a peice of hardboard or plywood,or metal.Keep the unknown in a sealed plastic bag.If you handle the unknown or asbestos panel do so carefully-do not break or cut it,or anything to cause it to shed fibers.Wear a dust mask and eye protection while handling it.