A closet, DIY box, cabinet, options are endless. I decided to convert one of my refrigerators into a grow box just yesterday, finished this morning. I have a grow room readily available, and I also have a closet I can use to grow. I've found that the fridge is the best thing I've used so far. My temps have never been so spot on w/ a nice humidity range & the white reflects light like a heaven. You remember the 80's movies with bad special effects where you would see the fridge being opened and you're bombarded with light...yep, that's it

You can pick one up off craigslist for probably 10-20 bucks non-working. If you want to control the humidity by the fridge, find a cheap one that's working.