A square electrical box molded in one-piece of plastic material has three ENT connectors extending outwardly from each box sidewall. The connectors on each sidewall include a middle connector and two outer connectors. All of the middle connectors are sized for receiving one-half inch standard trade size ENT conduit. Both of the outer connectors one one pair of opposite sidewalls are sized for receiving three-quarter inch standard trade size ENT conduit. The other pair of opposite sidewalls have one outer connector sized to receive three-quarter inch standard trade size ENT conduit and another outer connector sized to receive one-inch standard trade size ENT conduit. The box has attachment ears extending outwardly from the box corners along diagonal lines that extend across diagonally opposite ones of the box corners. An adapter attached to a front surface of the box has attachment ears aligned with the box ears. Fastener receiving holes through the attachment ears are configured to receive fasteners that are inwardly inclined toward the box central longitudinal axis.