First of all. YES, SHROOMS NEED LIGHT. It doesn't have to be special, sodium/ phosphorus/ halide/ high pressure XXXXX just any light. Any small desk lamp, shining on them from above. Light is what tells the mycelium to start forming pins and then fruit. When mycelium sees light, that tells it that it is running out of nutrients and to start growing fruits. 12 hours light + 12 hours dark. Trust me, it makes a difference.
After 6 months though, it sounds like you need to start over.
In the future, when you take the cakes out of the jar, put them in a pot or pitcher full of clean water and leave them in the refridgerator over night. This will make sure they have plenty of water and you wont need to spray them at all. Also, a drop in temperature tells the mycelium to start fruiting. I would also avoid putting wood powder or any other substance near the cakes or in the same chamber. I don't really have a good picture in my mind as to how your setup is set up but here is a cheap easy way to grow cakes in a fruiting chamber that does everything itself. Use a cheap aquarium pump to blow bubbles under the rocks, and poke a few holes in the lid, and you have constant fresh air exchange. You can also put an aquarium heater in the water to raise the temp.
http://www.shroomery.org/9047/Poor-Mans-Pod