Amanda Bynes

Amanda Bynes attends a court hearing in New York. (Neilson Barnard / Getty Images / July 9, 2013)

Actress Amanda Bynes remains under an involuntary mental health evaluation, but a court order will be required to keep her in custody for much longer.

Bynes was detained Monday by Ventura County sheriff's deputies after a bizarre incident in which she set clothes on fire. But those holds typically only last a few days.

Her parents are considering seeking a conservatorship similar to one obtained for singer Britney Spears, according to a source familiar with the "Hairspray" star's latest run-in with authorities.

Her parents, who for more than a year have expressed concerns about her welfare, have discussed seeking a conservatorship for their daughter, according to a source familiar with the actress but not authorized to discuss the matter publicly.

Britney Spears parents' obtained a conservatorship after a series of erratic incidents in 2008, including a much-publicized visit to a salon where she had her head shaved. In Spears' case, her father has overseen her life with a court-ordered attorney since she was deemed legally incompetent.

Under a conservatorship, a person turns over the most basic decisions in life about money, doctors and even where they live.

Bynes was stopped after igniting a her pant leg while setting a small fire with a gas can in the driveway of a Thousand Oaks home, according to deputies and witnesses. The actress grew up in Thousand Oaks, where her father had a dental practice.

PHOTOS: Celebrity mug shots

Bynes, already facing drug charges in New York and the subject of a series of charges in L.A. County, was taken into custody for her own safety under California's Welfare and Institutions Code, known as a 5150 hold, after the incident, Sheriff's Capt. Don Aguilar said.

In Bynes' latest entanglement, a witness who called 911 reported seeing Bynes with a small gas can and was concerned it could explode.

Andrew Liverpool told reporters he saw "this girl lying down here with her left pant leg on fire and there is this gas can right here and it is trailing fire."

Liverpool said when he went to help, she had already managed to snuff out the flames on her pant leg.

The witness said Bynes was with a small dog and that when the man asked if she was OK, she said she was fine.

As he was moving the gas can away and others arrived to help, he said, Bynes left the scene and he found her on the next block. He said she then tried to leave in a cab, but he told the driver not to take her.

"When I look at her," he said, he realized "it is Amanda Bynes." He said Bynes claimed that her dog had been burned.

Deputies responded to a home in the 200 block of Avenida de los Arboles about 8:46 p.m.

"There was a call about a small fire that she'd apparently set in front of the residence, kind of out on a sidewalk on the concrete," Sgt. Eric Buschow said. "It wasn't an attempt to burn down the house or anything."

Buschow said the fire caused no property damage.

ALSO:

Mission Viejo man faces 120 years for child molestation 

Gay immigrant spared deportation because of bias in Philippines

Abcarian: Anthony Weiner's wife wants to reassure us. Don't trust her.

Twitter: @lacrimes| Google+

richard.winton@latimes.com