the first three digits were the same, but our house ended in 4434 and PP was 4348.
Did the exchange prefix (first three digits) happen to end with a 4, e.g. 234-4434 ? Combinations like that can sometimes cause some people to erroneously add an extra digit or omit one. If someone misread the number and inserted one too many digit 4s, then they'd get you, with the last 8 digit they dialed being ignored as surplus.
It's well-known in the telecoms industry that certain number patterns are easier to remember than others (no surprises that a big corporation will often ask for a number such as 260-1111 or 260-5000 rather than something like 260-1938 or 260-0482), and that certain numbers are subject to more frequent misdialing due to digit insertion, omission, or transposition.
I had an example of the latter where I lived once: My number was 441761, while the number of the local Chinese takeout was 441671. It wasn't
so frequent as to become annoying, but every so often I'd get a call asking for chicken chow mein with fried rice or asking "What time are you open until?"
Bell/AT&T actually commissioned a study way back in the beginning of the 20th century to test how a selection of users would take to using dials, by having them dial lots of numbers of varying lengths, of different compositions, and with the digits grouped in different ways, and recording how accurately different numbers where dialed on average.