Wwyd?

Sorry if this doesn't belong in this group, wasn't sure where else to put it!

So we just moved into our new house about a month ago. We haven't really had a chance to meet many neighbors, but we live on a quiet no outside street a ways down from a busier area. On our street, there are no street lights or anything so once it gets dark,it's dark.

Basically it was around 930-945 at night and my husband and I were cleaning some things in the living room. Well, out the window we see the house across the street has all of its lights off, but the car in the driveway is flashing its lights like an alarm, but it isn't making any noise or anything. This goes on for about 10 minutes after we noticed it, and I was debating whether we should call the police non-emergency line in case it was an attempted break-in, but my mom and husband both felt I should leave it alone. The lights eventually stopped flashing so maybe they were home and just didn't see it right away? But there were still no lights on in their house. For now gonna just keep an eye out and be vigilant... but what would you have done in the situation?