Since relocating recently I’ve found I’m picking up that irritating mobile phone noise on my HiFi- that familiar tick-a-tick-a-tick-a-tick fzzzzzzzz every few minutes. Switched all phones off and it still occurs. I know there are various ways to guard against interference but what puzzles me is where is it coming from if our phones are switched off? Could it be the neighbours phone or some other device? Any mobile phone/tech experts out there can advise?