I installed LED strip lights in place of the stock cabin light, but
running four feet, almost the full length of the cabin above the table
and stove.  It lights up the whole main cabin quite well.

I'll try to find time soon to take photos and write it up in detail.

> Thinking of putting the strip under the metal strip on the edge of
> the top bunk. Good place?

I thought about doing that, but I wasn't sure how to shield/diffuse
them, so they wouldn't be annoying when sitting on the bench seat to
work.  So I didn't mount any there, but I did mount the on/off switch
and dimmer potentiometer in that metal strip, near the sliding door, so
I can easily turn on the cabin lights from outside, after opening the
door but before stepping into the cabin.  There's not much room inside
that metal strip, so the geometry was interesting.

> Thinking of either wiring into the galley light ...

I removed the galley light and used its wires for power to the LED
dimmer module.  I tried a couple of dimmer modules.  The one I have now
works well, but I'd like to find an even better one.

> What size wire should I use?

Depends on the maximum current, of course.  Again, I'll try to find time
to write that up in detail.

> Thinking about adding a strip outside the slider so we have some
> lights at night.

How to protect it from the weather?  I think that use case might be
better served by a rechargeable light.

Sorry I never wrote up this project.  Maybe I can get to it this weekend.