Roxie, home VPN solutions are mainly for folks who, for various reasons, want all their communications encrypted so that no one can snoop on them or learn their IP address or geographic location etc. Another use for VPN is that some folks want a website to think they're in a different country. Ex-pats abroad who want to access BBC iPlayer is one example.
When you're at home, the communications between your wireless devices and router are encrypted which means that if anyone intercepted that data they wouldn't be able to make any sense of it. Likewise, when you do online shopping or banking your data is encrypted in the browser and can only be understood by the legitimate website. However, some folks who frequently use unsecured wireless public hotspots may want a VPN solution on their mobile device - for example if they use an email service that doesn't support encryption.
So to summarise, I don't think you don't need a VPN at home.