Hi @wanderinggsouls :) This is a great question, and the answer is yes, you can use fake candles. Candles essentially have three primary uses in witchcraft; to symbolise an idea, to act as a focal point, and to provide energy. Fake candles can do all of these things.
For example, you can use LED candles - you can even get very convincing looking ones made from real wax that flicker. LED candles can be used to symbolise an idea (e.g. god & goddess on an altar), especially if you're able to get them in different colours. LED candles can still act as a focal point during a spell; you can stare into them whilst visualising your goal. This effect is made better if you get realistic ones that flicker. Thirdly, LED candles can provide energy for your spell like any other. They are battery-powered, and this energy depletes as the LED "burns". So just like a real candle provides energy, LED candles do too.
There are drawbacks, of course. You can't really anoint them with magickal oil, or carve symbols into them. You can't let them burn all the way down or dispose of them ritually. But these are all minor concerns if spellcasting is your goal; they can still assist your spellwork.
I actually made a YouTube video on alternatives to candles, so for more information on this topic you can watch it here: https://www.youtube.com/watch?v=3g9RwAsrvro
I hope this helped :)