I live on my own and have a Key Safe fixed to the side wall of the house. You choose a 4 digit code and set it according to the instructions , and anyone can access the numbered buttons as long as they know the code, which then allows the safe to opened and key retrieved. I got mine from Argos.
My family know the code, and my next door neighbour who I've known for 30 years and trust totally
I was taken into hospital last November, having been sent there direct from my appointment with my GP, and was there for 3 weeks. The Keysafe was really useful as my daughter and family came down from Cheshire at weekends and used the key to get in the house and stay there for the weekend.
So far, I haven't locked myself out, but have done so in the past, so its reassuring to know that if I do it again I can retrieve the key¬