Do the morality police in Saudi Arabia make people pray five times a day?

no,... its up to each individual.... Saudi employees many people from around the world that are of different faiths.. they will never force anyone to pray

If they are at home, the morality police will not know whether they pray or not.

Of course not.............

Think about it. What better way to keep control of your people than to make them show up at a mosque five times a day, all line up in nice rows s you can count them? And if someone misses prayers a few times, those around where he usually goes start asking "Where is Akbar? Maybe we need to check up on him."