wall switch in Excella 1990 32'

[femuse]

We just bought a 1990 Excella 32' and are trying to fix and understand a few odds & ends.
The dealer told us that the switch in the bathroom, even though labelled "high/low", is not supposed to operate on low setting.

These vanity lights are a real power drain. We want to check the wiring & make sure it will be High AND Low.

I tugged on the switch, it did not come out. Before I break it, I want to make sure there is no special trick to removing it.

Any truth about that switch originally working only on high?

(Yes, I know: the power is off, 12 & 110 volt) .

Thank you for your input.