The best location is INDOORS in any location that is naturally humid, or you can easily keep moist. So a bathroom or laundry is perfect. It doesn’t need to be in the dark. It likes deep shade, so indoor light is great.
If your kitchen is large enough that might work. Some people grow them in their garage or shed, but make sure it’s not to dry is safe from flying insects.
The worst place is anywhere there is a draft, or in direct sun. Dryness is the enemy of your mushrooms so take care where you place it.
NOTE: you only really need to do this for the 4 days it taks for the mushrooms (fruit) to grow. The rest of the time just keep it in a spot thats slightly warm, but not to hot – and away from drafts or things that might dry it out.