Bah!
No IT component, just some makering.
My wife, daughter and I used to decorate our house for Halloween with a "wrought iron arch" and fences (actually panels from an old "tent" gazebo corner bits strapped to the fence with black cable ties and festooned with purple lights). We had a small graveyard in the little garden you had to walk past to get to the front door, with bones and skulls and bats and so forth, and I seeded the lawn with some nifty flats I made from plywood that made ghostly shadows of, er, ghosts and black cats. Passing cars would throw shadows from the matte black painted flats that were very effective.
All designed to be "six year old scary". We left "terror" to the neighbour five doors down, who had a "working" electric chair out front. One Christmas he was executing Santa in it. I digress.
Each year we would go to the post-halloween sales and add to the kit at rock-bottom prices. I picked up six sets of "ghostly marching footprint" lights for a song one year, enough to make for a ghost padding alongside the pathway as trick or treaters dared the front porch.
Every year it was the same. Before sunset mothers would turn up with their youngsters and ask if they could photograph their kids in some part of the display. After dark is was Dads with kids in tow, and they would hang back at the gate while the kids came in for candy.
One year, towards the end of the era when the nabe had young kids, I splurged and bought a smoke machine. Of course, the problem is that the "smoke" is actually hot glycol-based vapour and it goes *up* in the cold November air. So I made a fog chiller. I started with an old 40 gallon beer cooler, and cut three inch holes in each end near the bottom. I glued in some PVC schedule 40 pipe with gorilla glue and connected the two ends inside the cooler with a pipe made from chicken wire.
I built a "U" bend from pipe so that the fog machine could sit on the cooler and shoot the fog into the bend, through the cooler and out through a two-foot extension pipe I fed into the graveyard foliage. Eight three pound bags of ice went into the cooler, forming an "ice-pipe". Still with me?
When it got dark I turned on the fog machine and slow-moving clouds of ground-hugging fog enveloped the graveyard. Passing cars would dissipate the fog quickly and any wind at all was disastrous of course.
But that night the Halloween Gods were on my side and the wind dropped and the traffic was non-existent for once. The fog built to Hammer House of Horror levels across the entire property. The black cat flats were poking out just enough to show heads and tails, and kids would be walking shin-deep in the lovely stuff.
That night I opened the door for the kids and was greeted by the sight of a garden full of wandering dads trying to figure out how the hell I had managed to fill the garden with horror-movie fog.
An hour or so later the traffic picked up and it was all dispersed.