THE ONE LEGGED MAN

I haven't seen my neighbor in at least week. He is about 91 years old and only has one leg. His car hasn't moved and his grass hasn't been cut ( he has a riding mower in case you were wondering how he cuts the grass with one leg). He lives alone. The only light I have seen on in the house in the one in his sun room. But it has stayed on for at least a week. Here's the thing. He is horribly mean. I want to go check on him but I am scared he will yell at me if he is alive! What do I do? Do i ring his door bell anyway and hope like hell he doesn't chase me off his stoop while swinging his prosthetic leg at me or do I call the police and let them deal with it?