Here are photos of my push button switch install on the Service Panel of my F3T.
Round button opens the garage door. Opener is taped to the underside of the panel.
Small socket is for powering my heated gear.
I used the area in the lower half of the Access Panel. The upper half is available for switches
and controls that extend deeper into the cavity.
Sloppy images but you get the idea. Red/Black wires are for heated gear.
Black and White wires are for the garage door opener.
Blue tape keeps the wires secured.

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