It looks like the interior of a train., but...
There was an episode of the old Mission Impossible TV show where the IMF team fooled a man into thinking he was on a sinking submarine so he would give up a secret code. The final reveal was that the entire submarine was a fake that had been built in a warehouse.
If secret agents need to create a fake train, they might contact Jason Shron, who built a twenty-foot-long replica 1980 Canadian Via Rail train car in his basement.
His obsession with detail and love of trains comes in handy; he runs a model train company called Rapido Trains.
The Guy with the Train in his Basement