Sounds like an old, redundant cooker switch, Gness. I must admit, I would like to see what's in there if only for curiosity's sake.
Even if it's a live circuit that has been terminated, there will still be a barrier between you and whatever it is/was when it's tiled over again.
Most older kitchens will have things like this. Just left over from previous layouts. It's your call entirely, I'm afraid, but I would suggest that most electricians would want to get in there to satisfy themselves.