I've made quite a few of these little window pop up cards. Some Halloween, some Christmas, some others here and here.
This greeting card has some ghosts. I borrowed the 3-ghost layout idea from a pennant on Bird's Cards. The ghost is the letter O dingbat from the Trick or Treat font. I modified the ghost a bit!
How to make a ghost silhouette paper window pop up card
Download pop up card files: PDF, SVG (How to use my files in Cricut Design Space) , DXF, Silhouette Studio.
Files download for free; contribute what you wish. Suggested amount for this file is $1.00.
Cut and score. On the PDF and JPG, cut lines are black, score lines are red.
Starting at the top, with the "good" side of the card facing you: valley fold the top score line; mountain fold the next score line; valley fold the two small score lines on the sides, near the bottom of the window; valley fold the score line at the bottom of the window.
Collapse the card and glue it into a base card. Glue the center parts of the letters A, P, and O into the letters.
More assembly tips for this type of card here.
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.