01
If it is safe, stop using the affected sink and place a container under a small drip. Move items out of the cupboard without touching electrical fittings or wet cables.
02
For water that continues to escape, close your internal stop tap if you can reach and operate it safely. Do not force a stuck valve. Call a plumber if the flow cannot be stopped.
03
A clear photo of the fitting and a wider view of the pipework can help explain the problem. Mention whether it leaks continuously or only while a tap or appliance is being used.