I used to get that too, it was in my old house.
I doubt it's sleep paralysis (when your mind wakes while your
body is still sleeping), because when I moved house, this problem
stopped immediately. The only other time I had this encounter in
the new house was during 7th month, after that, no more
encounters.
If it's sleep paralysis, it's biological and it would have
persisted in my new house too.
When I was in the old house, I used to go out very late.
Sometimes me and the neighbourhood kids will play hide and seek in
the old Toa Payoh Hospital, we even hid outside the
morgue.
During one of my "your so called sleep paralysis", I heard a
Malay man chanting.
I kenna once at my old place during the 7th month before
I woke up drenched in sweat and I was blasting my air-con
too
I could hear someone talking to me in a foreign language in my
ear
It sounded very urgently and desperate and I couldn't move or
scream so I prayed and it just faded away
I went to take a shower coz I was totally soaked through in a
20oC air-con room :x