I live by myself, each morning as I sit down to eat my brekkie, I send a messenger OK to my daughter who lives and works locally. If she did not receive this by 9.00 am any morning, she would try to telephone me, if no reply, she would come round.
Simple, easy and cheap. So, at the very longest I could go without someone finding me if I was is 24 hours. Have done this for several years.
My eldest daughter always has a weekly 'catch-up' call each weekend, which I really look forward to and can often last most of an hour. My other two daughters ring me occasionally, more likely for me to ring them and also my son similar.
However all of them phone me on my birthday - which is rather pleasant.