Added a slow red, LED flasher from Evan Designs to the top of my Lionel Sand Tower. Drilled a hole through the top of the Sand Tower about the diameter of the lens, but less than the lip of the lens. Put a little CA glue around the lip and pushed it up into the hole from the bottom and applied some accelerator to secure it in place.
Ran the wires down the back of the far leg so they don't show and secured them to the leg with CA glue and accelerator. I had pre-drilled a hole in the layout to run the wires through and did that before pushing the 4 legs securely into the foam. (Note: this Lionel Sand Tower comes from the factory with the 4 legs attached to a flat metal base so you can just place it on the layout and run track on top of the metal base and through the tower. Since my whisker tracks were already laid and ballasted, I couldn't do that, so I carefully removed the legs from the metal base and spaced them out evenly from the sides of the track.)
The flasher has a built-in resistor in the wires so it can run off 10-19 AC volts, which is convenient, so I just hooked it up to my 18acv track power distribution board and it starts working as soon as I apply track power.
One other note - the flasher flashes red, but the lens is clear. I wanted the lens to be red so it would show up even while off and painted it prior to installation with Tamiya Clear Red, so the lens appears red when off, but is "translucent" enough so it does not substantially diminish the brightness of the LED light.