How could I conceal exposed outlet wiring after electric baseboard heater removal?
Some ideas, in order of preference:


Drop the wiring down from each box, under the floor (which would allow you to remove the shelf board)
Bring the wiring up under the shelf board where it's mostly hidden.
Overlay a one-by board with a minimal gap behind (maybe right behind the blocks on which the faceplates are mounted)
Run Wiremold&trade; or similar in beige or tan