how to Remove ghost files and folders still taking up space after deletion

Terminal code to clean DocumentRevisionsfolder…

https://apple.stackexchange.com/questions/313102/what-will-occur-if-the-documentrevisions-v100-folder-is-deleted

macos - What will occur if the .DocumentRevisions-V100 folder is deleted? - Ask Different (stackexchange.com)

System Memory OS 10.12.6 Sierra - Apple Community

System Memory OS 10.12.6 Sierra - Apple Community

4 suggestions…

Look for iOS backups…

/Users/YourUserName/Library/Application Support/MobileSync/Backup

OmniDiskSweeper shows you the files on your drive, largest to smallest, and lets you quickly Trash or open them.

https://www.omnigroup.com/more/

Purging local backups

Please note that although this doesn't affect your remote backup from Time Machine, this will get rid of the redundancy (at least until the next Time Machine backup) that a local backup disk will provide. If you need such redundancy or are worried about the recovery of your data then you would be best served to let macOS determine when to purge these files.

Start Terminal from spotlight.

At the terminal type tmutil listlocalsnapshotdates. 

Hit enter.

Here, you'll now see a list of all of the locally stored Time Machine backup snapshots stored on your disk.

Next you can remove the snapshots based on their date. I prefer to delete them one at at time. Once my "System" disk usage is at an acceptable level, I stop deleting but you can delete all of them if you want to reclaim all of the disk space.

Back at the terminal, type tmutil deletelocalsnapshots YYYY-MM-DD-HHMMSS , where will be one of the dates from your backup. This will be in the form of xxx-yy-zz-abcdef. Try to start with the oldest snapshot.

Hit enter.

Repeat for as many snapshot dates as required

http://www.thagomizer.com/blog/2018/03/27/cleaning-up-time-machine-local-snapshots.html

tmutil deletelocalsnapshots /  # deletes all the snapshots

BobHarris file sizes…

sudo du -hx | sort -h 

sudo du -hx ~/| sort -h 

We need to see what all is running, a report from this will not display any personal info...

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.

https://www.etrecheck.com/

Pastebin is a good place to paste the whole report if you capture the URL while there…

https://pastebin.com/

Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...

Delete these files & restart...

~/Library/LaunchAgents/org.freedesktop.dbus-session.plist

~/Library/LaunchAgents/org.virtualbox.vboxwebsrv.plist

~/Library/LaunchAgents/com.valvesoftware.steamclean.plist

/Library/LaunchDaemons/com.adobe.acc.installer.v2.plist

~/Library/LaunchAgents/org.getlantern.plist

/Library/LaunchAgents/com.adobe.ARMDCHelper.cc24aef4a1b90ed56a725c38014c95072f92651fb65e1bf9c8e43c37a23d420d.plist

~ tilde indicates your home folder

Apple hid the Users' Library folders...

Method 1:

1 From the Finder, select the Go menu at top of the screen, and choose Go to Folder.

2 In the window that opens, enter ~/Library, and click Go.

I highly recommend this App...

App Cleaner & Uninstaller - Remove Apps from Mac Entirely (nektony.com)

To give you an idea of hw many hidden things there can be...