From time to time discussions of vault doors have included noting electrical contacts for alarms. Here's another example. I don't remember seeing this on a side bolt of a rectangular door. Other than indications that the image is from 1938, no other information has been found. It's also an impressive number of steps on the door itself.

Click image for larger version. 

Name:	Vault-Bank.jpg 
Views:	13 
Size:	65.8 KB 
ID:	22573 Click image for larger version. 

Name:	Vault-Bank 2.jpg 
Views:	14 
Size:	82.9 KB 
ID:	22574