I say the house was "supposedly" in the film, because I watched "Lonely Hearts" but never pinned down which scene featured this home. There were several houses that might have been this one, but there was never enough of a wide shot to confirm this. However, it's a fact that "Lonely Hearts" was shot primarily in Jacksonville, in the Riverside neighborhood, and as I was taking pictures of the house, some people came out to tell me about its movie role. Here's a side view of the house.
It's obvious the house was long ago subdivided into apartments, but the fading charm of the one-time grand single family mansion is still there.
My guess is this house was built in the early years of the last century. While not restored, it is still a handsome reminder of those times.