If you don't know exactly what you're doing, get an electrician in. Electricity can kill.
Quite happy thanks, just never seen this type of switch before.
No fuses within grid switch but could be that grid switch feeds a fused spur word of warning fuse is a safety device and if blown it went for a reason and unless that reason is found and rectified do not replace the fuse
I have seen a fused spur hidden in the chimney of a cookerhood before, might be worth a look.