Pests are always a problem.
Build nanobots that can crawl your garden, detect the pests on your trees and plants and destroy them one by one.
If you are away, your home may become a target.
A remote “house sitting” service that visits your home every day (at different and unpredictable hours) and produces “signs of life” so anyone watching it will think people are regularly there.
It’s a bore to lock and unlock your bike, especially if you use it a lot.
Have sensors that activate when your bike is at rest and pressure on the wheels/tires is reduces (bike is being lifted.) or bike is in movement. When you park your bicycle, just turn on the system, and if someone tries to lift or move the bike, a loud alarm is activated.
Private and small swimming pools are unattended many times, and that can be dangerous especially for little children.
When sensors indicate that the pool has not been used for a while, a net is automatically stretched across it so that anyone who might trip into it will be suspended unharmed above the water.
On one hand, you would like the have protection against intruders. On the other hand, you don’t want to get stuck inside in a case you need to escape (for instance in case a fire breaks out.)
Build a mesh from steel of small “joints” that only allow movement of this joint in on direction. A window could have such a mesh installed, and since the flexibility is only in the out direction, intruders could not go in because, from the outside, it would be stiff as steel. You would also need to build sensors into these joints to monitor contact. When you trough yourself at this mesh from the inside, these sensors will register the contact, and if enough of them register that (meaning there is a significant mass leaning on the mesh from the inside), a release mechanism will activate and allow you to escape. You could also build into the wall a slow cable release that – in case you are in a high building – would slowly descend you to the ground inside this mesh, helping you escape.