In the 1990: we have 6 vanity lights, 13w each, look like plain old bulbs to me.
(Mike asked: aren't tungsten filament bulbs just the plain old type bulb ?)
bulbs in 15, 25, 40 and 50 watt ratings
I didn't know they made them that bright.
What we have done in our 1974, on the 2 ceiling lights in the kitchen/dining area:
Mike has rewired the fixtures and arranged the bulbs so on click #1 we have as low a wattage as we can get: one 5w automotive bulb. Enough to eat a pizza or have a drink.
click #2: I think we must have 3 bulbs: enough for most dinner.
click #3: 5 bulbs: better use this one if you eat fish with a lot of bones. Rarely use it.
He couldn't figured out how to get the right combination to use the 6 bulbs, but 5 are enough and it works great that way.
Your trailer may be more like our 1974: the bathroom fixture has 4 bulbs, and a rotating switch with 3 positions. The bulbs look alike.
The problem in the 1990 bathroom looks pretty different. Bigger base and different types of bulbs. A rocker type switch High/Low.
The high/low is an absolute necessity: we don't need the same wattage say for brushing our teeth than when Mike has to trim his mustache (rarely, but...).
I guess we will have to start experimenting.