Telephone
From Tardis Wiki, the free Doctor Who reference
A telephone was a communications device used on Earth.
In 1941, the Empty Child was able to Hom-Com with the TARDIS's police box phone. (DW: The Empty Child)
In 1968 the Sentience was able to cut off all phone lines from Crook Marsham. (NA: Nightshade)
The Master fitted a extra-long phone cable to the Doctor's phone in his UNIT lab with the intent of using it (and the Nestene Consciousness' affinity with plastic) to kill the Doctor. (DW: Terror of the Autons)
Vardans were able to transmit themselves down telephone wires. (NA: Return of the Living Dad)