It’s a two-part sign. The lower part gets anchored to the wall. The upper part is attached to the lower part, but it gets “cantilevered” a bit out into space.
Back view of the lower part:
I later added a PWM motor controller so the LED brightness could be controlled, allowing running them at less than full brightness, to run cooler and extend their lifespan.
With cutting plexiglass, the thing to avoid is heat buildup — because the plexiglass will get melted and gum up around your bit and melted plexiglass will get thrown off throughout the room. So do use a feeds and speeds calculator setup for cutting plexiglass and trust those numbers. If you try to go slow, you can wind up with the spinning bit camping out too long in any given location and heat building up. You usually have to cut it faster rather than slower to keep the melting from happening.