I kept pet fancy mice for over ten years, males and females. They love fleece to snuggle into but I wouldn`t really advise hanging it from a height as their claws can sometimes get caught, so you don`t want him twisting a toe or a leg. Look for things that can be placed on a shelf or on the floor ideally, although pocket hammocks (enclosed hammocks) can be hung lower down. A tank might be trick for hanging things, so a narrow barred cage is a better choice for mice, especially males as they tend to smell more.
In the UK there are sponge igloos sold for mice and other such things that they love to hide out in. You can rip up plain white toilet tissue and place this inside too as a nesting material, which is safe.
Male mice need to live alone anyway due to their tendency to start fights with another male. They can be neutered to allow them to live with female mice, but it carries risks. Many live alone fine if they are already used to it.
The Rodent's Nest
This website is a mouse forum so have a look at the caging/housing on there and see what other mouse owners have/advise.