A light fixture includes a housing enclosing a light source. The housing defines an opening therethrough. A plug, which is receivable within the opening, includes a face having a central knockout portion. A perimeter of the knockout portion defines an opening size smaller than an opening size of the opening. According to alternative configurations, the plug may be removed from the opening or only the knockout portion may be removed from the plug while leaving a remainder of the plug in the opening. As such, different sized openings through the light fixture housing may be provided for installation of various light fixture accessories.