I made a steam boiler plant out of a small Lionel building to heat my Maintenance Facility. Probably was a small office building. I stuffed a smoke unit in that I found on A..zon which is actually for a radio controlled tank. The stack is 1/2" EMT conduit with an LED blinker wired up the middle and mounted on top. Smokes great and it was fun to build!
I don't use track voltage. I used an old DC transformer from a portable phone for the smoke unit, which I run sporadically. The LED blinker runs off a USB cell phone charger @5VDC and I seldom shut it off. Blinks all the time, just like the LED in your computer.