It is possible that your Wi-Fi network is running on an old router which is using the legacy encryption mode: WEP. Currently Sprite is only compatible with Wi-Fi networks secured by WPA. The WEP encryption is weak which can be broken easily. You want to be aware of this and turn directly to WPA, a stronger encryption mode. If you are not familiar with setting up the Wi-Fi routers, Please refer to this article: http://www.wikihow.com/Change-WEP-to-WPA
It is also possible that your router is an old one and runs on Wireless-B(11Mbps). Sprite only supports the newer standards, namely Wireless-N, Wireless-G and Wireless-AC. We also found that if the SSID (name of your home Wi-Fi) contains special characters like spaces or quotation marks, Sprite might have difficulties in connecting to it.