Router on different ring main

[underleigh]

My PC & router is in my office in the grounds of my house but on a different ring-main. I have hardwired a telephone link to the main house but wifi is poor due to the distance. Could I connect another router to the same line in the main house to give wifi connection there?

[MHC]

Only if they are NEVER on the line together.    Two powered up - neither will work,  one powered up and teh there off,  it will seriously attenuate the signal and result lowered through put.

Whu not run an Cat5e/Ethernet cable from the existing router to where you want a WAP?    Just follow the telephone cable.