When somebody rings or texts my iPhone it is now also showing up on iPad when I'm at home. This is happening since we had internet installed at home, so whoever is on the iPad sees all the calls and messages.
This is a feature in iOS since version 8. You can turn it off. On the iPhone, go to Settings/Phone/Allow Calls on Other Devices and turn it off entirely or just off in the "Allow Calls On" section at the bottom. Also on the iPhone, go to Settings/Messages/Text Message Forwarding and turn off this feature for the iPad (or turn it off entirely).