Finally got light rays that can be seen.  Had to use the light ray material on a cone.  Using a conical spotlight would not work. 

Bryce crashed and I lost the first try at this - Note to self... save often and use incremental file names. 

Need to work on a bunch of stuff -

• Material for wall has to change (not sure what that triangle is in the upper right corner). 
• Floor texture may or may not change.
• Outside the window will be something. 
• Clouds and atmosphere needs work.  Want it a bit darker in the room.
• Add more stuff to attic.  Chair in place to see if room height is OK.  May raise the roof.

Second try -

• Light bulb is going.
• Need to work on the light more
• Still don't like the wall texture. 
• Work on sky - I want a darker more gloomy atmosphere.

Final version.  Wall texture by jba (hard to see at this size, but looks nice).  Used a different floor texture.  Added more stuff.

File size 32MB,  Render time little over an hour.