Telegraph

The telegraph was one of the first form of communications technology developed on Earth, during the 19th century.

The Excalbian recreation of Abraham Lincoln referred to Uhura's communications system as a "voice telegraph device."

Worf used components of a telegraph, in combination with his communicator, to create a personal deflector shield against projectiles in the damaged holodeck simulation of Deadwood. 

While a salvage team lead by Miles O'Brien was stranded on Empok Nor, it was suggested that if the field coils in the deflector grid were modified to emit a series of covariant pulses, while the power was boosted to the induction grid, they could use the station "like an old-fashioned telegraph and tap out an SOS" to send to Deep Space 9.