An antique bronze telegraph used by the military in the mid-1800s. Its maker is unknown.
Telegraph Island is a small island located off the Arabian Peninsula and part of the Oman Islands. It was used as a staging post between England and India. There was a military outpost there in the 1860s, but it was shut down after every soldier that was posted there went violently insane. Since then the islands been abandoned.
In real life, Telegraph Island was not an easy posting for the telegraph operators there, with the severe summer heat and hostility of local tribes making life extremely uncomfortable. Because of this, the island is, according to some travel agents and journalists, where the expression "go round the bend" comes from, a reference to the heat making British officers desperate to return to civilization, which meant a voyage around the bend in the Strait of Hormuz back to India
Somehow, whenever someone taps the telegraph it interferes with their brain wave patterns (causes a rhythmic disturbance), causing severe hallucinations. Also, the user will keep hearing the telegraph tapping everywhere they go. It displays the qualities of an "earworm" or "sticky tune", a persistent, irritating tune which the hearer can, nonetheless, not get out of their head.
As explained in a deleted scene, the telegraph may only effect those whose minds have been conditioned to take orders, a trait shared by Pete with his marine background, and the isolated soldiers from the island.
The catalog card for Telegraph Island reads:
A remote outpost between England and India in the mid-1800s.
Reported that every soldier posted there went violently insane.
"Did not seem to effect [sic] non-military personnel to the same extent."
"Has not affected anyone since the end of the empire (Agent Brant)."
Whether the card says Telegraph Island or the telegraph(s) themselves have not affected anyone other than the soldiers stationed there is unclear, but it is implied to be the former.
It was discovered after Warehouse Agent Pete Lattimer played with it out of curiosity, while tracking Brigadier General Laverlong's Elephant Walking Stick at the British History Museum in Lakefield, Illinois. Pete unconsciously began to create a paranoid delusion, gathering details from his life in the manner of a dreamer, and began living in a fantasy world his mind created. It became harder and harder for him to tell reality from fantasy, and he eventually went mad.
Agent Lattimer was returned to reality after his brain was exposed to sensory overload, which seemed to reset his brain and undo the effects of the telegraph. He suffered sensory overload after listening to Tito Puente's Original Studio Master of "Oye Como Va".