In the middle of fitting a new kitchen and managed to drill through the cable (buried in the wall) that leads to the cooker on/off switch. Husband says he can fix it by joining the cable but I'm not so sure. Any advice or information would be much appreciated, thanks.
If the cable is buried in the wall (rther than in conduit or behind a stud wall) then it can be repaired, although as above this isn't ideal, as the repair can fail over time. on any circuit the weak link is joints. Really this should be done by an electrician to ensure it is done correctly. It's quite a common call out!
It will involve making quite a large hole in your wall though, probably around12 inches long and 4 inches wide.
lock up your husbands tool box!