Hi Ted
I haven't ever heard of livein volunteer carers and my first advice (please don't take offence) would be to get DBS check done because no one should invite anyone in without first being DBS checked.
That done, I have heard of FOCUS - I think it is a church group, probably Cof E who befriend people and also Age UK I think have befrienders.
It might be worth making enquiries with local residential care homes or with the local hospitals or hospices to see if there is a voluntary role.
I think you need to think extra carefully about protecting yourself against any safeguarding concerns from relatives, social services etc who may query your motive and intentions. Sadly Volunteers are a rare breed but don't let that put you off , but far better to do it through official channels.