Ticking Noise Inside A Wall

I have this really annoying ticking noise inside my wall and wondering if anyone could help me?

It's happening inside a top floor apartment.

From what I can tell:
1. Happens on an internal wall close to where the sewerage aeration pipe is (but it doesn't appear to come from it)
2. Happens throughout the daylight hours but not much at night
3. Doesn't seem to be electrical as I've switched off power to the entire lot and the sound keeps going
4. Doesn't seem to be plumbing as I don't think there are any water pipes in that wall
5. HVAC is switched off and no ducts are in that wall

I've attached a video showing the ticking where it's loudest by putting a phone camera into a power point hole.

https://1drv.ms/v/s!AvmFjt08wu3Rgswieq-7svmb0vqrPA

the benefit of metal framing

I lived for many years with metal roof on metal framing and it wasn't as 'regular' as that sound.

It is indeed a cladding building on steel frame with tin roof. It sounds like a banging but no idea what to do.

I have someone with a boroscope coming to look.

Hope that finds the cause. With our house the ticking would 'never' be heard at night, it was only during changes in temperature during the day but it wasn't as regular as your sound, or as loud. Actually I quite liked the ticking because if a storm was approaching I knew that ticking meant rain had started to fall and as the roof sheeting cooled then the ticking started and the washing could quickly be rescued from the clothesline.

Apparent cause was builder had missed rubber washers under the roofing screws. Once you know what a noise is and if it's not causing problems, it's a whole lot easier to live with...and ignore.