Dorothy Heard, from Galashiels, was working alone on the manual board at Buccleuch House in Melrose when she suffered the shocking ordeal.
She revealed she had been busy connecting calls from sports reporters at the local rugby grounds to the offices of the national newspapers based in Edinburgh and Glasgow when the exchange board lit up.
Recalling the drama this week, Dorothy said: "Saturday was a very busy day because you had all your sports reporters phoning from all the rugby grounds round about and the majority would be calling the papers in Edinburgh and Glasgow. As soon as the game was finished the whole board lit up, it really did.
"Melrose telephone exchange was a manual exchange in a house and the switchboard was in the back room of the house, but the switch gear was also in the same room, and it was a terrifying affair if you were working when it was thunder and lightening because the lightening used to dance along the switch gear in the room when you were there.
"And if you were on a Saturday afternoon you were on on your own, even getting away to the toilet was a handful. You had to time it, because you knew when it was going to be busy and if it was Melrose Sevens you just didn't get away."
The former supervisor is organising a reunion of former telephonists across the Borders at the Kingsknowes Hotel in Galashiels on Wednesday, November 7, at 12.30pm for 1pm, and is inviting other former employees along to share their experiences.
Margaret Tancock first joined the telephone exchange in Galashiels after spotting the vacancy in the Borders Telegraph in 1965.
However, she revealed the idea to hold the first reunion of staff from the telephone exchange for 26 years only came about after we printed an old photograph of the High Street board in a recent edition.
Margaret said: "It was very old fashioned when I first went into it." But she added: "The good days were when the boxes of chocolates got passed round the board, folk sent them up for Christmas; or when Duncan McKinnon sent up free tickets to all the dances that he put on in the Borders that he ran."
Anyone interested in attending the reunion should contact Dorothy or Maragret in advance by calling 01896 755690 or 01896 756204.