Interesting ~ I have never heard of Tulpas - but I have thought of having multiple metaphysical people in my head, since I was a child ~

on an INTJ board, someone asked: "If the inside of your mind was a room..." and this is what I have:

The size of a medium apartment - a large portion built into the wall is a filing cabinet - light beige, filled with photos, memos, dictionaries, theological texts, music manuscripts etc. There's a pile of stuff in the corner: musical instruments, pens, camera, computer etc. Some people occupy the space: a pre-teen girl, a dark hooded figure with dark eyes, scruffy guy, mathematician, half-naked-muscly guy There is a plain square table in the room, and some comfortable upholstered chairs scattered around it. The girl is smiling and grinning, warm fire burning within, the dark figure has a smirk, and is resting back observing everything pensively. The others are in a state of zen and calm, the mathematician is snoozing comfortably, naked guy is covered in sweat. There is a trap door in the corner of the room opposite the filing cabinet. under the door there are other figures - fear, anxiety, feelings of entrapment - they only surface at times and they sometimes hold the other occupants hostage - but can't get them into the trapdoor itself.