We’ve got 4 of these mounted along the centreline of the roof, each controlled with its own switch (as well as a master switch for the whole ceiling light circuit).

They’re wired up, but hanging loose at the moment, as we don’t have the roof cladding in, but they look simple enough to fit, just using a silicon or rubber back section to provide a friction fit in the panel. Nice quality.

£13 each from 12V Planet.