This is a true experience of someone who was kind enough to share this with me.

It was on this Diwali day (festival of lights, celebrated on new moon day). It was around 8.00 in the night. He was watching children bursting crackers. All of a sudden there was an intent urge in him to go into meditation. He went into his room and sat on his chair (the place of meditation and seat for meditation should never be changed). He felt an extreme pressure on the top of his head (known as brahmarandra, an extremely subtle orifice; this is known as adhipati in Ayurveda; it is one of the marma points). Generally, when there is pressure in sahasrāra, which happens without any notice, one remains disconnected from the surroundings. This experience could last for a few seconds to one or two minutes and very rarely, it could last long.  Two things happen during this state. In most of these occasions, one sees light and nothing else. In rare occasions, one receives Divine commune, where something is revealed to him such as a mantra, or meaning of some word, etc. Vedas were revealed to ancient sages in this manner only.

During these times, his eyes are closed involuntarily. When this person closed his eyes, there appeared a crescent moon (probably like waxing moon on the tenth day). The outer corner of the moon was deep red and the moon appearing like the normal moon. After sometime, the moon disappeared and total darkness prevailed. Almost immediately, there appeared a light like a flame. First the bottom of the flame became visible and gradually, the top of the flame became visible. This time, silhouette of the flame was blue. The flame also disappeared after sometime. He opened his eyes and realized what happened to him. When he came back to his consciousness, he could hear the noise of bursting crackers. Probably, the whole thing would have lasted for two or three minutes or even less than that.

I requested him to tell me about the significance of this particular experience; he said nothing and with a naughty smile on his face, he walked away.