A cafe may include a food purchasing area, a primary dining area, and a primary child play area. A second cover slidably is movable in a direction perpendicular to its visible surface. The cable unit with an optical module has an optical cable that includes a plurality of optical fibers and an optical module provided at two ends of the optical cable. The springs provide sufficient tension to the covers to block small children from inserting fingers or foreign objects into a receptacle, preventing inadvertent exposure to hazardous voltage.