Over the years electrical wiring standards have changed massively. What was once acceptable is no longer good practice but in older houses it can be usual to find lots of out dated writing. Often this only becomes apparent when you come to have work done on your home by an electrician. Although you may not legally need to change it, it can be good practice to get your wiring updated.
Often you may find that lights and sockets in your home do not have an earth. This is a safety feature which is now installed in all electrics but was not mandatory a number of years ago.
If you find that your electrics are tripping then you may have a fault that needs to be investigated.
An electrician will be able to carry out a test on the property to try and establish if there are any faults. Unfortunately, often they cannot tell you exactly what the fault is until they have done more checks and tests and this can be costly. If you need a full rewire you may have to fork out over a thousand pounds depending on how big the property is and how much work there is to do.