Your search for "closure switch" revealed the following:
RGH-40: Ganging hardware
$30.00Description: 1/4–20 x 5/8 hex and kep nuts (40-pc. bag). Model No. Description Size Package Type Quantity RGH-40 Rack ganging...
P625X: RECESSED BACKBOX
$30.00Recessed steel backbox (6.25 in. square, 4 in. deep, .090 cu.ft. volume) features side knockouts and an undercoating with sound deadener....
UNIHORN LUH-15T: 15W HORN
$202.00Ready-to-install 15W horn engineered for labor-saving installation in brick, concrete block, plaster, drywall or acoustic tile—recessed or surface-mount applications. Includes...
SVP: Steel vent panel
$19.00Steel vented panel, flanged (18-ga.). Black smooth semi-gloss finish SVP Series: 35% open area and .625 in. flange Model No....
LFD: front door
$122.00Surface-mount front door (solid steel, fully-vented or smoked Plexiglas) with lock fits 19" racks in series: LDR, LER, LER-F, LGR,...