I would think any electrician could do a cable tech or alarms tech with some training, I don't think it would work the other way round. But I suppose the training for an electrician is usually an apprenticeship( collage time involved (3 years? ) day release.Whereas a cable tech is a lot shorter training.
The sparky is a lot more scope.
( Not that I would know of course, I used to be a Tiffy
so a sparky wouldn't trust me as far as he could throw me
)