I’ve just replaced my smoke alarms as the old ones were out of date. They were in from when the house was built and the wiring too. The 3 core and earth had the outer grey sheath stripped quite far back (approx 4-5 inches) possibly because of the ceiling plate that housed the alarm (brk). I just wanted to know if this is acceptable to leave as is? As I’ve pushed it back up into the ceiling void to cater for the new alarms (Aico). Don’t ask for pictures as I can’t get any currently. Thanks.