are you aware of what 'bonding' is and why its important?
From the picture, it is not apparent that the bonding is in place.
Nothing wrong with tightening the screws, just so long as you don't tighten them too much (can cause conductors to break)
Lack of CPC in lighting suggests that the cable was installed pre 1966
Diagonal cables hidden in walls.
Bonding not apparent.
CPCs not sleeved in fuse box.
Unidentified wires simply cut off in back boxes.
What other sins are yet to be found?
Have you called a spark yet?
Good news about the switches being plastic at least.
From the picture, it is not apparent that the bonding is in place.
Nothing wrong with tightening the screws, just so long as you don't tighten them too much (can cause conductors to break)
Lack of CPC in lighting suggests that the cable was installed pre 1966
Diagonal cables hidden in walls.
Bonding not apparent.
CPCs not sleeved in fuse box.
Unidentified wires simply cut off in back boxes.
What other sins are yet to be found?
Have you called a spark yet?
Good news about the switches being plastic at least.