Hey everyone, New to this forum, it thought it was worth a shot. I recently moved into a house that has a couple of rooms that have half hot receptacles controlled by switches. In testing the outlets that are operated by the switches I found that the tops are all constantly hot as expected. The bottom half of the receptacles all show "open hot" until the switch is in the on position,at which time they show as wired correctly. My question is, if this is how these receptacles are supposed to show on the tester? Also all of these rooms are on the same circuit, not sure if that makes a difference, but thought it might. Thanks in advance for any input. P.s I am a novice at electrical work.

I recently discovered, accidentally, that two circuits in my house use a common neutral. Is there some reliable method to detect if there are other circuits with common neutrals?