Funny

Would be funny if this is how gun control becomes a thing in America. A bunch of greedy landlords unable to overcharged people for rent because the neighbourhood is deemed unsafe start lobbying the government to get guns under control because it's affecting their bottom dollar.

I think "pranks" that involve misleading everyone in audible range into fearing for their lives would reduce property values regardless of open house timings

Well, as long as it's near the bowling alley.

There has to be a way to improve this. The problem is that you have to refill the cap gun. Could you instead do something similar with a solar-powered compressor and a small pressure chamber? Can you make a realistic gunshot sound with a pressure tank and appropriate plumbing?

If such a thing could work, you wouldn't even need to install it in an easily accessible place. This thing here needs to be a little library because the cap gun needs reloading. And a free little library is one of the few acceptable reasons for a random person to install a big box in a public place.

But...if this were a system that just compressed atmospheric air to be released periodically as "gunshots?" Then you could put them anywhere; they wouldn't need reloading. You could install it on a power pole or up in a tree. Anywhere that can hide a small box and a little solar panel. Hide it somewhere that's difficult to find. Hell, you could sneak them onto people's rooftops via drones at night! You might be able to make some sort of methane fuel cell and hide the damn things in the sewer.

Oh, and be sure your gunshot simulators have some RNG built into them. You don't want gunshot sounds coming from the same fixed set of locations every time there's an open house. Better to have 20 gunshot generators scattered across a neighborhood, hidden in all sorts of creative locations. Tune the RNG so that every third house showing experiences at least one simulated gunshot. And don't have them coordinated. Make each individual box roll its own dice to determine whether it will respond to an open house. And if mechanically possible, allow for variable numbers of shots! Feel free to also add loudspeaker that will make the gunshot sound be accompanied occasionally with the angry yells of men of non-white ethnicity. Or possibly the sound of an angry man shouting in Spanish or Arabic.

Ooooh... if you could mount the system high enough, and build the appropriate automated gimbling system...you could use a highly directional speaker to direct a cone/beam of sound just in the direction of whatever houses had open houses that day. It would be like an automatic gun turret, except instead of bullets, it broadcasts gunshot sounds and the shouts of angry men at open houses.

Oh man, this is fun to think about. The possibilities are endless!

Random question but where can one get a little library (sans gun)?

Several people have died a block away from my building over the years. I personally have been in two fights right outside. Rent has only continued to go up.

I live somewhere where we have had multiple stabbings directly outside in the last year or so. Our rent is still increasing. Our landlord spoke to the landlord of a property that is in much worse disrepair near us and saw cash in his eyes.

Please tell me it shoots downwards and not up into the air?

So… the longer rentals aren’t rented, the higher prices go until the local rental economy collapses and properties get sold off to decentralized management firms, who are willing to gentrify a group of properties until they can raise the rent floor on everyone.