[The Installer]

Sorry Kymmy but as jb66 says the telco line voltage is 40-45 volts and 75volts when ringing. None of the Telewest kit i have ever come into contact with has been 90 volts.

As for cable modems broadcasting RF, yeah maybe they do but at such a small level it will be irrelevant.

To the OP, if you use a mobile phone a lot, there is your problem. I would strongly suggest you use the loudspeaker on your phone all the time instead of clamping it to the side of your head. Also use a handsfree car kit if you use your phone on the move.

If any RF leakage is coming from a cable box, it will be too small to cause you any headaches and going through a wall just makes it even more unlikely.

The other thing you might want to look at/for is do you live right by a mobile phone base station? If there is one less than 100meters from your place, this would be a much more realistic thing to look at/investigate.

HTH