Obviously, it depends on the type of philosopher:
Empiricist: We can’t know how to change a lightbulb, but we can make lists of how big it is, the wattage, the thickness of the glass, the composition of the filiment…
Skeptic: We can’t know if we’re changing the lightbulb. We can’t know if changing the lightbulb is an improvement. In fact, we can’t really know if it’s dark. Especially with the lights out.