Here is the scenario:
Halloween night, you're at a (surprise) Halloween party...working or hanging out with friends/family etc. The majority of the time these places are going to have dim lighting to set the atmosphere which is perfect for what you are going to do next.
You do a basic routine at the table to draw people in, then you pull out a miniature coffin (they do exist, just Google it) just big enough to hold a playing card. In this case a Bicycle red backed Hofzinser, with a light source shining from underneath showing a 3 of clubs.
You open the lid, letting everyone see the 3 of clubs.
You take a deck of Bicycle red backed cards and fan them out asking for a spectator to select one, they do so, you tell them to have a look, (10 of Diamonds) show it around but to not let you see it. Then you ask them to replace their card into the deck, after this is done you close the coffin lid.
You can create some patter about the Shadow people (supernatural shadow-like humanoid figures) or think up your own patter, while doing cuts, shuffles, etc....have them wave their hand over the deck to cast their own shadow over it.
Do a ribbon spread face-up showing all the cards are there...except for one, their 10 of Diamonds, in it's place is a blank-faced card.
You open the coffin lid once more showing a Bicycle Ghost backed card...you take it out of the coffin, lay it face down on the table or in their hand and turn it over slowly revealing their 10 of Diamonds.
- Steve