Any suggestions to reuse these lanterns?

Maybe put candles inside the lanterns so they are still a source of light versus having to wire them!

You could turn them into lamps, floor lamps, pendant lights or wall sconces. You can get lamp kits at hardware store and use any variety of materials as the base.

Since the plastic/glass looks a little dated, I would consider replacing it with decorative punched out metal sheeting. Would definitely make them look less commercial and probably be easier than trying to get custom cut glass.

Removing one panel of the glass will leave you with a nice 3 sided open space to decorate with seasonal themes.

I would replace the glass with clear and then use a Luminara candle inside. You could put other things inside depending on the season - shells, Christmas balls, etc.

It would be interesting if you replaced the glass with decorative metal sheeting that's flared slightly to make a planter out of the lamps. You could even suspend them or affix them to a porch post and make them into strawberry pots or grow herbs in them.