Swear words are usually used as fillers in sentences.
"Dollars and Sense"
Col. Wm. C. Hunter
She read jokes and recipes and answers to correspondents, and small editorial fillers as to the number of nutmegs consumed in China yearly, and the name and circumstances of the oldest living man in England.
"Sisters"
Kathleen Norris
The old weavers set them low in the picture, used them as space-fillers wherever space lay happily before them, and they never exaggerated their size, a virtue of which the full Renaissance cannot boast.
"The Tapestry Book"
Helen Churchill Candee