Enter a haunted house

As stated, all you gotta do is walk in the house

Get Jumpscared

Die to the ghost

Throw out a Trash Bag

Load up a contract that has the objectives of sweeping up piles and throwing out trash bags. After sweeping up a pile it will produce a trash bag. You can pick this up with E and drop it with m1 and walk very slowly out to the container.
By playing through the game and completeing objectives you can slowly work your way through the tiers of Garbage Collector achievements

Clean up a Trash Pile

Load up a contract that has the objectives of sweeping up piles and throwing out trash bags. Listen for flies buzzing around as they will indicate an objective. Take out your dust pan and sweep it up, the achievement will pop.

Help up a fallen Teammate

There are medkits scattered around each map and you can buy them in the lobby screen. Wait for a teammate to be killed by the ghost then revive them with a medkit for the achievement to pop. (Im not sure if this works for a self revive in single player but it works for co-op obviously)

Find a key

On all maps (minus 47 Strafford Lane having no attic) there are basement, garage, master bedroom, and attic keys. You can find any one of those for the first time and the achievement will pop.

Read a diary entry

On the maps 358 Bridle Street and the Haunted Duplex on 22 Willow Lane, there are diary entries that you can read to gain some lore on the location. By interacting with E on any of them you will gain the achievement.

Dispose a Moldy Pizza

Load up a contract with the “dispose of moldy pizzas objective” and listen for flies as it will help you find them. Interact and dispose of the pizza and the achievement will pop.

Complete a job without being chased once

Id recommend doing a quick and easy job such as unclogging the 4 toilets on 47 Strafford Lane. Make use of the closets around you if you hear the breathing or footsteps of the ghost. The red light is also a dead giveaway if you see it down the hall. If you get chased just restart the contract or finish and try again.

Turn the electricity back on

On every map, there is a power box that controls the electricity. The spawn changes every time but has fixed spawn locations. On 358 Bridle Street they spawn in the basement or the garage. At 47 Stafford Lane it spawns in the basement or the garage as well. At the Haunted Duplex on 22 Willow Lane It can spawn in the basement, garage, or outside both the basement and garage doors on the outside of the Duplex

Complete a Job without getting downed

Similar to Nothing to see here, do an easy job and pay attention to your surroundings. Energy drinks and closets are your friends.

Complete a job on any difficulty

Complete all the objectives on a contract of your choice and live to tell the tale.

Unclog a Toilet

Load up a contract with the objective to unclog any amount of toilets. Grab your plunger from spawn and find that diabolical toilet. Plunge through the nasty noises until the meter fills up entirely and the toilet is unclogged.

Collect 20 Toy Rabbits in the Haunted House on 358 Bridle Street

There are 20 little orange bunnies littered across the map that give money and xp per pick-up. Attached is a guide from a fellow player that does a great job of showing the locations. Ty!

https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=2957752407

Collect 20 Whispering Paintings at 47 Stafford Lane

Similarly to the bunnies, there are 20 brown rolled up paintings that emit a faint whisper when you are near them. Attached is my guide on where to find them!

https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=3367880344

Collect 20 Bones in the Haunted Duplex on 22 Willow Lane

You know the drill, 20 bloody bones can be found on this map and below I have attached a guide from a fellow player. Ty!

https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=2957813707

Complete a job in under 5 mintues

I actually created a detailed guide for this as my first-ever guide on steam! I have attached it below.

https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=3367709860