I had a similar mushroom growing in one of my amaryllis, except mine was much fatter, and there were a LOT of them. When I unpotted the amaryllis, the soil was chock full of mycilium, and I had to bring out the 'big guns'-- wash the bulb clean and then sterilize with a fungicide. If your mushroom reappears you might want to get rid of that soil. Happy gardening! --Rick in CT

Insulation nicks (unless the wire was touching some other conductive surface) wouldn't cause a failure. However, if the conductor itself was nicked, it would now have a higher resistance due to the decreased cross section. It could quite well locally heat up at that point and further degrade. Chances are it was that and movement through thermal cycling (heating up and cooling down). Once it gets to the point of arcing it can get really really hot. Normal wiring protection via overcurrent breakers sized to the wire assumes that the wire is intact and won't heat up with currents less than the breaker. All that goes out the window with a poor connection (bad contact, smaller than rated wiring due to nicks, broken strands) and arcing. It will get hot in a hurry. THis was a major motivation for the AFCI changes.

Sounds like the temps are probably fine. I'm concerned if it might be TOO warm all closed up like that. Is there any way to set up a fan full-time? Maybe turn the fan off at night, but leave the lights on at night and let them get their DARK hours during the afternoon/evening? That's what I do... I turn my lights off from late afternoon until around midnight so the heat from the lights keeps them warm through the night. Of course, you have to have a pretty dark garage(in the day hours) to pull off this maneuver--- plants need their dark as much as they need their light. Kevin

Assuming you are talking about setting your plant pots inside this box rather than planting directly in it and that you don't allow heat to build up in it then "the-more-reflective-the-better" and foil will reflect the most. If you will do a bit of research on on 'hydroponic grow boxes' you'll find this is quite common. Plus over on the Growing from Seed forum here there are many discussions about using foil coated sheets like those cheap foil emergency blankets to enclose shelves for seed starting to increase the lighting. Dave