It is a cork reamer for making holes in corks.

Noble Gases T-Shirt, Medium, Dark Grey.

It's a neon electrode housing. It is mounted into a hole in a (usually) metal sign. The neon is mounted to the face and the electrode protrudes into this housing making an electrical connection to the neon transformer.
Neatoramabot T-Shirt, M, Ash Grey

Yo thanks!