The starry background die is from Simon Says Stamp, the buildings in the background are from Memory box, the little ghosts and sentiment "eek" is from Savvy and the window cut out is Spellbinders Wonky Rectangles.
The patterned paper is one I had put aside to use on a different card but, decided to use it here, I think it's from a 6 x 6 Studio Calico pad.
The patterned paper is "popped up" a bit with dimensionals with the acetate sandwiched in between so raw edges aren't visible from the inside of the card. The ghost die cuts are attached with mini glue dots on the front and then again on the inside in order to hide the glue dot. Same with the "Eek" sentiment.
I think acetate cards are super fun and often times I forget to use them. Shari Carroll in the Online Card Classes - "Insider" had some great acetate cards. Even though class is over, you can always sign up and enjoy the classes any time.
Be inspired! Try something new!