The Rent Reducer 9000

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.

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!
- Now that's innovation.

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.

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.

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.
- As if. Bye bye neighborhood library boxes.
  
  Cool. I made mine look like a traffic cam
- Would be funny if this is how gun control becomes a thing in America.
  They're way more likely to outlaw little free libraries. Also, people are gonna notice that the little free library in their neighborhood smells like spent gunpowder.
  
  Could just hide a speaker in a tree or something. Hell hide them all over.
  
  Not when everything smells of spent gunpowder
- Is it that much different from how fun control became a thing in California?
  The "wrong" people have to start enjoying guns is all
  
  Join the SRA! (Socialist Rifle Association). We are the wrong people! We either arm the vanguard (not actually a goal) or we get more common sense gun laws implemented. It's a win win.
  In more serious terms, think of it as an organization where you can learn responsible gun ownership without being surrounded by maga hats. You don't need to consider yourself a socialist to join. Though there is a basic vetting process to keep the maga hats out.
  
  They'd just ban little libraries.

I think "pranks" that involve misleading everyone in audible range into fearing for their lives would reduce property values regardless of open house timings
- I want my property value to go down, it means less property taxes.
- The trick is to get an entire neighborhood in on it. That way you can schedule shouting matches in the front yards of the houses neighboring the open houses as well.
- If it fires upwards then it's not misleading at all.
  
  They're talking about shooting blanks
  
  Even if it wasn't shooting blanks, there's also wind, and trajectory and stuff like that

Well, as long as it's near the bowling alley.
- Homer's six-shooter shotgun.

Random question but where can one get a little library (sans gun)?
- https://shop.littlefreelibrary.org/
  
  Dang the official ones are expensive huh
- Depends. What kind of table saw do you have?
  
  None at all!
- Local hardware shop, some assembly required. Nothing says it needs to be extraordinarily fancy so long as it keeps the contents dry.
- In Holland people will just put old shelves on the street with some books in them and add a sign.
  
  I don’t even have enough shelves for the books I have, let alone old shelves 🤣

Please tell me it shoots downwards and not up into the air?
- Starter pistols, the ones for races.
- Why is shooting a starter pistol in the air a bad thing?
  
  It won't hurt no one, but it's the same principle as yelling fire in a loaded theater, in that it can get someone hurt if they freak out.
- Shooting actually straight up is very safe, at least for people on the ground. The terminal velocity of a bullet is fast enough to make you say "ouch", but not much else.
  Problems can arise if you're shooting up-ish, but shooting straight up means the bullet has zero velocity relative to its origin at the apex, so the only speed it has from that point forward is imparted by gravity and wind, pretty much.
  The image is of a starter pistol, though.