Options for Replacing T101 Rotary Timer With Switch
Replace it with a switch in a surface mount box

Once you get that switch and receptacle out of there (after turning the breaker off of course), you'll need to install a surface mount box -- I'd use a 4" square box with a single gang mud ring as handy boxes get tight quickly -- and use some cable clamps to bring the existing cables into the box (one will come in from the lower left and the other from the back right, from the appearances of things).  You may need a spare handy box as well in order to "jumbo pigtail" one of the cables to extend it with an extra length of 14/2 NM -- this will also be surface mounted, with a ground pigtail nutted in with the rest of the grounds and a blank cover over it.

You can then install a single pole switch -- the whites nut to each other, the blacks land on the switch hot (brass/black) screws, and the bare grounds nut to each other, a pigtail to a ground screw on the box, and a pigtail to the green ground screw on the switch.  Add a switch cover, turn the breaker back on, and enjoy!