We have had reports recently of calls concerning the setting up of emergency alert systems in your home. These are obviously targeted at elderly residents and suggest that they can arrange direct access to the emergency services including the Social Services departments. They usually also say that they already have people working in the area at the moment on properties close by.
Of course all they require is your bank details in order to set it up for you.
It is a scam.
Put the phone down and ignore it.