A srsnge Wi-Fi network on my I phone 7 8

No. Wifi is always searching for available networks, even ones you are not connected to. And if there is any network within Wifi range, it will show on your iPhone, even if you've not connected to this network, there is no cause for concern. And it most assuredly, doesn't mean someone is spying on your house.

You are picking up the signal of a neighbor's wireless network. You won't be able to sign on to that network unless you know the password for your neighbor's wireless network.

Your neighbor can "see" your wireless signal as well at his house. He won't be able to log on to your network unless he knows the password for your network.

From my house, I can usually "see" up to 5-6 other wireless networks. I can't log onto any of them because I don't know the password for those networks.