As some have mentioned Ghost electrical issues are really hard to diagnose especially if you are single lady, not wishing to sound patronising of course
.My best advice would be, if you are getting sporadic total power failure, e.g. everything is going off and on then it can only be a short/bad connection through the main power feeds in the car. Only way this can be diagnosed properly is take it to an auto electrician, NOT a mechanic or other auto engineer, this can only be found quickly by using the correct electrical diagnostic tools and techniques, mechnics whilst good are not electrical specialists anything else could just be a waste of money if they don't find the fault. Even the best mechanics could spend hours trying to trace faults when an autoelectrician can test every line from the battery right back through the fuse boxes/relays and should find the bad feed much quicker.
Best of luck