Doris over at Grans on bran got me thinking with her post about phone boxes.
I can remember when my Dad told us all if the next phone bill wasnt smaller then he was fitting a lock to the phone. So when the next bill came we were all prepared for the lock to be fitted
We had a trim phone

and not to disappoint us Dad sent the lock home with Mum with instructions to fit it straight away.
The lock was fitted but the hilarious thing was mum fitted it in the zero which meant you could still turn the whole dial round it took about a week for Dad to realise and fit it properly in the number one.
I dont know how we found out but someone must have told us that you could tap the lever that disconnected the call when you put the phone down, so we did that everytime we needed to use the phone. It was a case of tap it once for 1 twice for 2 and so on up to ten for a zero. It would have been easy if everyones number was 1111111 but when you tried to tap out a nine or a zero it got quite a bit more difficult which resulted in lots of wrong numbers each time we tried it. The best part of this was the look on Dads face when the next bill came and it was more than the last one! so of course we then blamed Dad for running up the phone bill.
Needless to say he took the lock off.