No such interference. Commercial power is operating at 50/60hertz, give it some transients still it wont go near CAT5 cabling frequencies of 100megahertz. Also noise cancellation is achieved by twisting the pairs of copper cable, if you are suspecting interference you could shield it up maybe by using a metallic cable tray that is strapped on earth ground.. Or.. Use a shielded twisted pair, you still have to connect it to earth ground thou.