An electrical box having spring legs for supporting the box within a space between a pair of spaced-apart parallel concrete forms. The legs engage the inside surface of one form and bias the open end of the box against the inside surface of the other form. The legs and the bottom of the box are cooperatively configured to facilitate attachment of the legs to the box. A bendable strap is attached to the box for wrapping around reinforcing bars within the forms. The legs and strap hold the box in position when concrete is poured into the space between the forms. The entire box and support elements remain embedded within the finished concrete wall, and with the open end of the box exposed at an outer surface of the concrete wall.