If you still have an old style fuse board, we recommend that you upgrade to the new 17th edition consumer unit which contains an RCD immediately.
If your fuse board is wood backed and has cast iron; ceramic switches, or a mixture of fuses, chances are, it could be over 40+ years old! That means it will not meet current safety regulations and MUST eventually be replaced.
An RCD, or residual current device, is a life-saving device which is designed to prevent you from getting a fatal electric shock if you touch something live, such as a bare wire. It can also provide some protection against electrical fires. RCDs offer a level of personal protection that old style fuse boards simply cannot provide.
Afterall, a fuse was originally designed to protect an electrical appliance and it's supply cable - Not the person switching it on (That was just a by-product)!