If worse comes to worst, you can always use a kitchen trash can. I've used them because my veiled never liked her small bin, so I'd leave her in a black kitchen trashcan with 12" of organic soil.
But if you have time to run out to the store, pick up an opaque, dark container that measures at least 12" deep, by at least 7-8" wide. You can fill it with moist play sand or organic top soil, both cheaply available at Home Depot/Lowe's.
But read Jann's blog for more details. I just wanted to say what I've used in the past.