Lucy's former house isn't exactly across the street, but it's on that same street anyway. I understand her former residence has been completely rebuilt. If you look at pics. of the house while she lived there, it has a slightly different look, with two small windows to the far right that aren't there now.
The house next door to Lucy's, however, belonged to Jack Benny, and looks pretty much the same.
Just as Lucy used a high wall by her house to film a segment for I Love Lucy, Jack Benny at least one time used the front of his house as an establishing shot, but for the home of Bob Hope, for some odd reason. George Burns also used an establishing shot of the exterior of his real house for Burns and Allen, and apparently the living room and kitchen set, as well as Burns' office upstairs in his garage, were all similar in layout to his actual house.
