I think I can remember in the past, being able to shift/click on a mummy to add him to my family. Is this still possible?
Does anyone know if I can add one.

I tried by going to one of the tombs in Egypt, but when I did shift/click, there was only the option to delete it.
So I put a sarcophagus onto my sim's lot at home, and using NRAAS, I was able to get a mummy to come out of it. But I still cannot interact with the mummy or add it to my family.

Can anyone help, please?

I actually managed to do it by using MC Add Sim.
It took a while, though, before he could interact with anything. But it all seems to be working ok now.