Undressing
This is not really possible without mods.
There are a few different mods, but the most popular is probably Dudestias Multiple Marriages and Spouse Dressup.
Note that this comes in two varieties, 1.0.0 and 0.9which one works best for you might take some experimentation.3; and If you're on console, I'm not entirely sure both versions do what you wantthe best link is, but my understanding is that most of console mods are also on Nexus, where you can explore the relevant category.
Sandboxing
Their behavior depends on the house they are in. YourWith just the base game, your spouse will never leave the cell in which they are housed, so they cannot for example join you outdoors unless you bring them along as a follower. (Which might be a bad idea, as many of them are weak.)
If you do bring them along as a follower, however, you have another option for undressing or redressing themAgain, the UFO.
These mods, of course address this, require SKSE and benefit greatly fromenable various options to customise the a mod manager, likebehaviour of spouses as if they were followers; NMMNexus seems to be the place to explore mods, and hope they are available for your platform if you're on console.