What a normal r1 = r2 result should be on a light circuit

[Pondy]

Isn't it now c3?

 

[GLENNSPARK]

c3...requires improvement

 

[TAZ]

If the circuit is short then the reading should be lower, I have had higher readings than i would normally expect & found the switch to be the problem as has been mentioned. Best to work your way along its length if that is possible.

 

[TaffyDuck]

A. 7 ohms is rubbish but within regs for a B6. ( Rule of thumb is advisory not a reg before anyone says its 6.18) .
B. Zs of 300 odd ohms? Depends on the earthing system, not sure what a damp wall has to do with it, its not IR.
C. I change maybe 5 faulty RCDs a month, anyone who relies entirely on a single RCD for protection is asking for trouble.

 

[Pondy]

I think the damp had got into the socket terminals and had corroded the copper hence the high resistance