this is a cable roller that allows you to take a long cable and leave it plugged into the wall and roll it back up when you are done. maybe something like this exists already but i couldn't find anything for my purposes. wanted it to stay rolled up and plugged into the wall.

3/8's bolt nut and washer

spring from an old broken pen and an air soft pellet work as the detent to hold the roller in place.

glue or press fit the cover on. I prefer press fit in case there are any issues you can just pop it off whenever you need to.