This is definitely a stress related problem. Was living in a very stressful enviorment and heard loud banging on wall three times (hard) and woke. No one said they banged on the wall. Would also hear my name being called from outside bedroom door and awoken but no one said they said anything. Anyway moved into a more relaxing stress free atmosphere and it all stopped. Was in my 30's at the time. Best cure relieve stress. Body does all kinds of strange things due to stress.