I highly suggest one. I came home on my lunch break once and realized I was out of bread. Turned around after having my hand on the doorknob. They were in the house at that moment. I got one the next day. Didn’t want my wife to walk in on bad guys.
I live in an apartment on the third floor in a 4-building apartment complex in a small city in central NY State. When I rented it 15 years ago, I took it because it was on the third floor, nobody over me. I was still working in NY State Corrections at the time, and figured if anyone was going to break in, they’d go for the basement or the first floor apartments. Why climb three flights of stairs to steal from anyone? There’s no balconies, and no access into my apartment other than my front door. There’s never been any break-ins in the complex since I’ve lived here. I always double-lock my door whenever I go out, and it’s always double-locked with chain lock once I’m home. My sense of security is still as heightened as it was when I worked Corrections. A security alarm system would be a waste of money for my small place.