I’m not moving anywhere

My heating and a/c has been making a really sound for the past two weeks! I am not exactly sure what on earth is going on with it, but almost every time the heating & undefined goes on, I hear this honestly loud screeching sound. That’s not the only thing, it kind of sounds care about something is rolling around in the HVAC ducts! There is no way I can jump into the HVAC duct to see for myself, so I let it go for a while. The other day, I observed I was not getting any air coming out of the air vents, so I ran over my neighbors house over who knew a thing or 2 about heating & cooling systems. He went up into the HVAC ducts & found that there was a small baseball stuck in there! How a baseball got into my HVAC duct & HVAC ducts is unknown, then but, my neighbor got it out of there, & my heating & undefined was flowing correctly at last!. The baseball was without a doubt in there for years before I moved in. There could have been youngsters playing, & then the baseball went into the HVAC ducts somehow, and possibly from the outside. The entire concept is confusing to say the least. I live alone & do not have any kids, so I am starting to wonder how I did not get the baseball stuck in the HVAC duct & HVAC ducts! I am just hoping that this is the end of anymore weird situations in my residence or my heating & undefined! But who knows, they consistently say to expect the unexpected. This for sure at the top of that category!