Alrighty, kids, I was able to solve the mystery of the unknown story. No one, as of the time of this writing, had suggested the correct source. Also, it seems like my commenters are a fair bit younger than me. XD Anyway, in case you’re curious, here follows the information pertinent to my quest:
The animated portion of the show I remembered was based on a story in a collection by Marilynne K. Roach, who also illustrated said book. It was entitled Encounters With The Invisible World. The story itself was called, fittingly enough, The Ghost In The Shed.
The show it was in was called The Incredible Book Escape, wherein P.J. finds herself trapped in a library after closing. The other memories I have are most likely other episodes in the series. Having looked over lists of titles included I found that I recognized them all, so I probably watched the show’s entire run.
It looks like I might be able to get a used copy of the old hardback. I always thought the cover looked cool, so I bet the insides will be too. Assuming, of course, that I actually follow through on this.
Case closed. Now, on to the next location.