Do ghosts have brains? I think so!
To scale to the size you need you could print the first layers of the model and test it.
It has two holes to add straps. On the ghost costume the straps are placed under the sheet.
Combine this brain hat with a bald head wig may be also a good idea.
Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!
Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!