Select a box suitable to house the bits and pieces and hang on the wall beside your door. Cut out the design or phrase of your choice and back with tissue paper.
Collect your bits and assemble on mounting boards hung within the box. As the image shows, I chose to mount the button below the housing, but could have just as easily placed it on the side or face of the box. Make sure to connect the timeout bit behind the buzzer or your doorbell with be both spooky and annoying.
Load some scary sounds or songs onto an MP3 player. Set the track(s) to loop so that when activated your spooky sounds will be ready to ominously emanate from within.
Attach a Lego Technic axle and tire-less wheel to the DC motor bit. Affix a small bat, skeleton, or 3-D printed ghost, to the end of a length of floss, running through a hole in the bottom of the housing. Conceal the spooky object in a cardboard coffin, behind a tombstone, or foggy cauldron below the mounted housing. Make sure to test your project a few times to get the length of floss right so that the object rises up to an appropriate height based on the timeout bit setting.