An assembly and a method for attaching a sign-type lighting fixture to an electrical box. The assembly includes a lighting fixture having a mounting plate affixed to the electrical box, an illuminating sign, and a canopy affixed to the lighting fixture, allowing the canopy and the mounting plate to attach quickly. The method first includes affixing a mounting plate to an electrical box and affixing a canopy to a sign-type lighting fixture. Next, the canopy is secured to the mounting plate by inserting at least one wing tab from the canopy through at least one holding tab on the mounting plate. Then, the electrical wiring is connected. After that the wing tab and holding tab are separated. Finally, the wing tab is inserted into at least one offset on the mounting plate, and the canopy is secured to the mounting plate.