Both of mine use the wire crates. I usually throw a blanket over the to too to make it more "cozy". I use mine to start out for potty training. Anytime I can't be watching the little ones they are in the crate. Kept very small at teh beginning. I section off a bigger crate. As they are more "trustworthy" they spend more & more time out of the crate. At the moment, both of mine still sleep in their crate & are there when we have to leave. They are not sectioned anymore so they have more room. This is to protect then from getting into stuff while we are away.
You should take their collars off in the crate, so there is no chance of getting caught.
During the day now mine are both out most the time, unless i need a break. They actually will go in it & take a nap, sometimes.
Make it a positive experienece. Not as a punishment.