Deleted videos appearing in Original Media folder

I'm trying to clean and free up space on my MacBook Pro, and while doing so, I decided to delete my old YouTube videos and project files. When I checked to see how large my FCP YouTube library was it said 59 GB. I had already deleted a bunch of videos and projects not only from the library, but also from my laptop at various times for the last two years. Today; however, I found no videos or projects that would add up to 59 GB. From Finder I right-clicked on the library, and clicked Show Package Contents to figure out what event was causing the issue. I found the event that is causing the issue, but in Final Cut Pro, there isn't any project or video file in it other than sound effects, one song, and three photos. I decided to open the event folder and then open the Original Media folder, and found that it was holding on to three old videos. Those videos are long gone from my laptop and Final Cut Pro, but may be on an old hard drive that I used as storage (I no longer use it). What can I do to remove those videos without potentially corrupting the library?

I'm using Final Cut Pro 10.4.10 and macOS Mojave 10.14.6