A much more difficult task was for translucent people. A human model is usually made of pieces and layers that are invisible in the usual way.

Many of the character 3D models are build using a texture for the body and head and separate textures for clothes over that body texture. This makes it easy to have different clothes using the same base-body. You can make the clothes invisible and change the body and head texture to a color. Then export and set the transparency. It's a little more difficult than this but it should give a good start.
You will be looking for models without too much detail that is difficult to remove. For example this one: https://free3d.io/?a=download&id=5ab719b4
Only a single texture but it is tif so you must convert that to png to apply it in sweet Home 3D. But for your purpose it doesn't matter (you don't need the texture): a full body to which you can set transparency.
(The 3D model is different from the one in the image)