In recent years, new ways of symbolizing the unity of two people have sprung up in place of the unity candle. One is using different colored sand instead of a flame to symbolize the union. This can be placed in an ornate bottle, and is something that can be displayed in the home without a second thought. It larger came out as an alternative for outdoor weddings due the the candles being blown out by the wind.
Here's another great idea. There isn't a great name for it, so we'll just call it the
Love Lock Box Ceremony.
It involves the couple writing
letters to each other describing their love, passion, and all the things that make them special or bring joy to each others life. They are not allowed to read one another's. These are
sealed up in an envelope and brought to the ceremony, along with a
bottle of wine and
a box. When the officiant gets to where the normal unity candle lighting would be, instead he elaborates on the the thought behind the letters and then
places them into the box, along with a bottle of wine. The bride and groom then help
seal the box.
The point here (which the officiant can elaborate on more during the ceremony) is for the box to remain sealed in case of such a time where the marriage is facing a potential breaking point, or for a 25th wedding anniversary

, that the couple will open the case...crack open the bottle of wine...and read each others letters...remembering all the things that helped shape the life they've created together.
Splurge on a nice bottle of wine, and be creative on the box....it could be wood and could be nailed shut as part of the the ceremony...could use a set-your-own-combination padlock with your wedding year as the combination.
There are tons of ways to do it. Look for something that fits your style.
Unity Candle Alternatives