All overhead lights in the house with the exception of two have wall switches; the one in the overhead bunk will remain switchless. Here's pics from when I added a switch to the kitchen sink light:
Switch wire ran from light:
Switch block and channel in their rough form:
Switch block/channel, and matching trim for the other side of the valence nearly complete sans finish:
Install complete - block & channel detail under valence:
While I was at it, I lowered the paper towel holder an inch. I originally installed it with a partial roll; when I installed a new roll, it was pressed so tight against the underside of the cabinet that it would not roll....