At first I was thinking it was an old Scientology E-meter. Since the orginal E-meters were nothing more than two tin cans, wire and a resistance meter, I decided against that vote.
I do believe it is a Block Signal Box. Basically, it was used for railway traffic control. If that's not what it is, then I have no idea.

YES! The underground bunker! It's like the artist went into my head and retrieved that thought. My concept was to bury a shipping container in my back yard and make it accessible through a refrigerator. You know, like, you open the fridge and instead of there being food and shit, there's a stairway going down. AWESOME.

**FACT CHECK**
Actually, there are over 100 Billion neurons in the brain and since the connections for each neuron multiply exponentially (eg. 2 neurons connect twice, 4 neurons connect 64 ways, 8 neurons connect 32,000 ways, etc.) After all is said and done, there are more possible synaptic connections in the human brain than there are particles in the known universe. Far, FAR more than a trillion which really is quite meager compared to the numbers we are talking about here.