I'm thinking about the possibility of designing a small device that would fit as a module as part of a wall outlet. As I don't wan't to deal with mains voltage myself, I thought about off the shelf solutions. One options is to use one of this (next to my own device, occupying another space in the wall box): https://http2.mlstatic.com/modulo-kalop-cargador-usb-doble-2-amp-carga-rapida-D_NQ_NP_684483-MLA26113488489_102017-F.jpg
The exterior case seems removable so I should be able to grab the USB power lines and expose them to the side. Maybe the USB socket itself is still usable after this mod. What do you think?
Looking into this I realized this kind of wall outlets vary greatly by country, so I'm not sure if others have these kind of modules.