I purchased LED rope light to provide indirect lighting from above crown
molding in a tray ceiling. LEDs were chosen since they don't generate heat.
I used clear plastic channel with mounting tape to hold the rope lighting.
The small angled blocks hold the molding. I had some other concurrent work
going on which allowed me to get electricity to the tray from the ceiling.
The first picture shows the lights installed with one of the crown pieces
in. The other shows the finished project.

Norm
Belleville IL