OK @johnthomas69, here we go:
My Dad died very suddenly and the following morning I was in my bedroom waiting for my DH to return from walking the dog so we could go to my Mum's and help her with stuff.
In my head I said something very specifically to my Dad - can't remember what but something like 'Dad I hope you are feeling OK now and not in pain'.
The room seemed to fill with sunlight, I got a very calm, peaceful feeling and his voice inside my head clearly said 'This is how I feel'.
Everything outside the room seemed to go really quiet but inside the room was absolutely filled with his presence, as you described it with your Mum, and I just stood there experiencing this calm and love and sense of everything being absolutely OK.
After a few moments I heard my DH returning and called to him to come and experience my Dad's presence but as soon as I called the light started to retreat so I asked it to come back and it did so. I didn't call DH again and could hear him pottering around downstairs.
A minute or so later the phone rang downstairs. Dad's voice in my head clearly said 'That's xxxxxx (my best friend), go and talk to her now'. And the light just retreated from the room. Not in a great swoosh like you describe - more slowly but really powerfully and I just knew nothing I could say or do would bring it back. It was totally gone.
So I came downstairs - and it was my best friend on the phone. I'd called her the night before to tell her the news but she'd been out and I'd left a message with her husband.
I know this sounds unbelievable to many, and I toyed with just sending my story to @johnthomas69 as a PM but then I thought some others might be interested. It was a life-changing experience, powerful and completely real.