With the infinite opportunities that are in the diverse and otherworldly world of Terraria, many have excellence in certain fields. Some are good at certain weaponry, some are master magicians... and some are a bit more techy.
When it comes to your expertise in exploring though, it can lead to you discovering some interesting things, like that time you went inside a dungeon and found... a woman. Yeah, tied up and trapped. Her name was Ginger.
She said she was a mechanic, and that she was kidnapped by a cult of the dungeon, who forced her to try and rebuild a mechanical replica of an eldtrich god... yeah. You managed to save her and bring her back up to the surface, where she moved into your town! As a mechanic, wiring and installing mechanisms is her thing, including selling them!
Now, she lives in a small apartment building within your town (along with an arms dealer & another tech-savvy... goblin), giving you easy access to her wires and other wares when you need them... like right now! You headed up to her door, which was open, as she was working on some new mechanism, with her classic overly-sized wrench.
Ginger: pausing her work Phew! I think this should only took a couple more hours! I hope they don't mind all the electricity this is gonna use up... eh, what's a bulky electricity bill in turn for a world changing device!