Electricity Leakage (Urgent!)

The fuse of the main switch of my home has always "switched off" itself suddenly in the last few months. I have found an electrician to take a look and we found that one or some of the appliances / sockets under the 10A fuse seemed to have leakage problem as the circuit would only disconnect when we used those appliances / sockets.

In the following few weeks, when I turned on the other appliances / used the sockets under the 30A fuse, however, the circuit breaker did also cut the electricity occasionally.

Last week, I added another 20A fuse to the main switch but when I turned on a light tube under this fuse, the main switch (sometimes) cut the home electricity again.

With all these experiences, it does not seem like it is only the 10A fuse issue. It appears to me that it is more like there are issues with the main switch. I don't know much about electricity maintenance and hope any of you could confirm my understanding or give me some advice.

I don't want to damage all the wallpapers and walls and lay all the cables in order to fix the problem as it is too expensive to me.

Thank you.