Lonely and spectral and sombre and still (line 67)
Another reminder of the tower of the church and the ghosts that live around it. By calling the tower "spectral," our speaker puts the theme of the supernatural back into the poem. He doesn't bring a lot of attention to this theme, but it gives this poem that kind of haunted feel. It creates a little tingle in your spine that keeps you absorbed, even if you don't quite realize it's there.
And the meeting-house windows, blank and bare, Gaze at him with a spectral glare (lines 97-98)
Even after we leave the church and the graveyard, ghosts keep popping up. Not real ghosts, in this case, but you can see how the windows of the town make for a spooky, blank face. The whole world, in fact, feels a little bit haunted in this poem. That's one of the things we really like about "Paul Revere's Ride." It tells a simple story, but it does it in a complicated way. It gives us a history lesson without being a textbook-style download of information.