[Spunky]

He couldn't have signed it. Although according to a minister he was only in Hospice a short time.

"Bishop Walter Thomas of New Psalmist Baptist Church, where Cummings worshiped for nearly 40 years, said he spoke with Cummings as he was going into hospice and said the congressman was there “for only a matter of hours.” Thomas declined to comment further, citing pastoral confidentiality."

"Cummings had not participated in a House roll call vote since Sept. 11. He missed a key committee hearing in mid-September, and his office said then he had undergone a medical procedure.Cummings had not participated in a House roll call vote since Sept. 11. He missed a key committee hearing in mid-September, and his office said then he had undergone a medical procedure......"

Rep. Elijah Cummings, Baltimore civil rights advocate and leader in Trump impeachment inquiry, dies

[Freee-dame]

Can someone take a document to a Congressman who is not in the House, or even DC, for his signature?

Some people can still think and are able to sign papers rather close to the time of their death. The signature might look different (shaky) but it is possible.