Vice President Kamala Harris will make a surprise appearance on “Saturday Night Live,” according to two people familiar with the plan, appearing on a live sketch-comedy show in the final days of the election as she tries to reach voters on a national platform with widespread cultural currency.

Ms. Harris is looking for any possible advantage with her contest against former President Donald J. Trump essentially tied and just three days to go. She spent Saturday campaigning in the battleground states of Georgia and North Carolina and was flying to Michigan when Air Force Two diverted without notice to New York City.

Appearing on live television is a gamble for a presidential candidate, or any celebrity without acting experience, but previous contenders have rolled the dice, including Mr. Trump and Hillary Clinton in 2015 and Barack Obama in 2007. (Mrs. Clinton also appeared in 2008.) Few have done so in the waning days of a campaign.

One of the most popular recurring features on “Saturday Night Live” is having actors portray presidents and presidential candidates. The comedian Maya Rudolph has played Ms. Harris to much acclaim. Even the vice president has praised her impression. “She’s so good,” Ms. Harris said last month on the ABC talk show “The View,” adding, “She had the whole thing — the suit, the jewelry, everything.”

“Saturday Night Live” airs on NBC at 11:30 p.m.

Michael Levenson contributed reporting.