You have a loose connection, probably in a receptacle that has been wired using the push-in connection. Start checking the receptacles on that circuit, and I'll bet there will be one that when you pull it out of the box, at least one wire will fall out. Put them back together using the screws.

Check any wire-nutted connections, too. Especially any with 4 or more wires. Some DIYers don't adequately ensure all wires are properly captured in the connector.

I have a newer constructed home with fairly new wiring and tonight my living room ceiling light and the outside light went out. Everything else in livrm is working including outlets. Checked the CB box/did the routine. I am stumped. Can anyone help what seems to be a very strange problem, however now that I am asking, the outside light is on the same switch plate the living room light is on. Hmmmm