How does this work?

1. Research basic Nanobot emitter.
2. Craft Nanobot gun.
3. Equip Nanobot gun in a weapon slot.
4. Craft either construction nanobots or termite nanobots and assign them as ammo to your Nanobot gun, just like ordinary firearm ammo.
5. Switch to the Nanobot gun (C on PC).
6. Walk near any ghosts or destruction plans, et voila!